In the early 2000s, astronomers discovered numerous Pluto-sized objects in the outer solar system, prompting a reevaluation of planetary classificatio...

Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!

Sentence Structure

Sentence 1:

• In the early 2000s,
  • astronomers discovered numerous Pluto-sized objects in the outer solar system, prompting a reevaluation of planetary classification.

Sentence 2:

• The International Astronomical Union voted to reclassify Pluto as a dwarf planet in 2006,
  • a decision that sparked widespread public controversy [?] maintaining that the new definition better reflected our understanding of planetary formation and orbital dynamics.

Where [?] = how to punctuate "however"

• A: ; however,
• B: , however,
• C: however,
• D: , however;

Understanding the Meaning

The first sentence sets up the context:

• In the early 2000s, astronomers discovered numerous Pluto-sized objects in the outer solar system
• This prompted a reevaluation of planetary classification

The second sentence tells us what happened as a result:

• The International Astronomical Union voted to reclassify Pluto as a dwarf planet in 2006

Then we get additional information about this decision:

• "a decision that sparked widespread public controversy"
  • The public didn't like this decision - it was controversial!

This is where we have the blank. Let's look at the choices - they all include the word "however" but punctuate it differently. To see what works here, let's read the rest of the sentence and understand what it's saying!

After the blank, the sentence continues:

• "maintaining that the new definition better reflected our understanding of planetary formation and orbital dynamics"

Now let's understand what this complete structure is telling us:

• The vote sparked public controversy (people were upset)
• "However" signals a contrast is coming
• "Maintaining that the new definition better reflected our understanding..."
  • This provides the contrasting view
  • Despite the public controversy, [the scientists/authorities] maintained that the new definition was actually better and more accurate

So the complete picture shows the tension:

• Public reaction: controversy and upset
• Scientific position (contrasting): the new definition was better

What do we notice about the structure here?

The key question is: What comes AFTER "however"?

• "Maintaining that the new definition better reflected our understanding of planetary formation and orbital dynamics"
  • This is a phrase starting with an -ing verb form
  • It's NOT a complete thought that could stand alone as a sentence
  • There's no clear subject performing the maintaining as a separate clause
  • It's providing additional descriptive information

Now, "however" can be punctuated two different ways depending on its job:

• When connecting two complete independent thoughts (each could be its own sentence):
  • Use a semicolon before and comma after: ; however,
• When functioning as an interrupter or transition within a sentence:
  • Use commas on both sides: , however,

Since what follows "however" is a phrase (not a complete independent clause), "however" is functioning as an interrupter here - showing contrast within the broader sentence structure.

When "however" interrupts or transitions within a sentence (rather than connecting two complete sentences), it needs commas on BOTH sides.

So we need: , however,

The correct answer is B.

GRAMMAR CONCEPT APPLIED

Punctuating "However" Based on Sentence Structure

The word "however" shows contrast, but how you punctuate it depends on what it's connecting or how it's functioning in the sentence.

Two main patterns:

Pattern 1: However connecting two complete independent clauses

• Use: ; however, (semicolon before, comma after)
• Each part could stand alone as its own complete sentence
• Example: "The decision sparked controversy; however, scientists maintained it was correct."
• Part 1: "The decision sparked controversy" (complete thought)
• Part 2: "scientists maintained it was correct" (complete thought)

Pattern 2: However functioning as an interrupter/transition within a sentence

• Use: , however, (commas on both sides)
• What follows is NOT a complete independent clause - it's a phrase or continuation
• Example: "The decision, however, sparked controversy among the public."
• "However" interrupts the flow within one sentence structure

How to decide which pattern to use:

Look at what comes AFTER "however":

• Can it stand alone as a complete sentence with its own subject and verb? → Use semicolon before
• Is it a phrase or dependent structure? → Use comma before

In this question:

• After "however" we have: "maintaining that the new definition better reflected our understanding..."
• This is a participial phrase (called that because it starts with a participle in grammar terms), not an independent clause
• Therefore: "however" functions as an interrupter → needs commas on both sides
• Answer: controversy, however, maintaining