In her comprehensive study, the historian examined primary sources including royal correspondence, such as letters between monarchs_____ such as ships...

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

• In her comprehensive study,
  • the historian examined primary sources including
    • royal correspondence,
      • such as letters between monarchs and personal diaries [?]
    • maritime records [?]
      • such as ships' logs and captains' journals,
    • and archaeological evidence,
      • such as pottery fragments and coins.

Understanding the Meaning

Let's start from the beginning:

"In her comprehensive study, the historian examined primary sources including..."

So this historian is looking at primary sources - original historical documents. The word "including" tells us examples are coming.

First example: "royal correspondence, such as letters between monarchs and personal diaries"

• "Royal correspondence" is the first category
• "Such as letters between monarchs and personal diaries" gives specific examples of what royal correspondence means

This is where we have the blank - we need to decide what punctuation comes after "personal diaries."

Let's look at the choices:

• They differ in punctuation after "personal diaries" and after "maritime records"
• To see what works here, let's read the rest of the sentence and understand what it's saying!

The sentence continues: "such as ships' logs and captains' journals, and archaeological evidence, such as pottery fragments and coins."

Now let's understand the complete structure. The historian examined three main categories of primary sources:

1. Royal correspondence
   • with examples: letters between monarchs and personal diaries
2. Maritime records
   • with examples: ships' logs and captains' journals
3. Archaeological evidence
   • with examples: pottery fragments and coins

What do we notice about the structure here?

• We have a list of three parallel items
• Each follows the same pattern: [main category], such as [specific examples],
• This is a straightforward list structure

In a list like this, we use commas to separate the items consistently:

• Comma after the examples for each category
• Comma after each main category name

So we need: commas in both blank positions

The correct answer is Choice C: "and personal diaries, maritime records,"

Grammar Concept Applied

Using Commas in Lists with Internal Details

When you have a list where each item contains its own internal descriptive phrases, you still use commas to separate the main items from each other. The pattern looks like this:

Basic list:

• The store sells fruits, vegetables, and grains.

List where each item has internal details:

• The store sells fruits, such as apples and oranges, vegetables, such as carrots and lettuce, and grains, such as rice and wheat.
• Main item 1: fruits, such as apples and oranges,
• Main item 2: vegetables, such as carrots and lettuce,
• Main item 3: and grains, such as rice and wheat

In our sentence:

• Main item 1: royal correspondence, such as letters between monarchs and personal diaries,
• Main item 2: maritime records, such as ships' logs and captains' journals,
• Main item 3: and archaeological evidence, such as pottery fragments and coins

The commas maintain consistent separation between list items, even though each item contains additional information. This keeps the structure clear and parallel.