The tech startup DataFlow revolutionized mobile payment systems with its innovative encryption app _____ the company quickly expanded operations to...

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

• The tech startup DataFlow
• revolutionized mobile payment systems
  • with its innovative encryption app
    • (2017)[?, and]
• the company quickly expanded operations
  • to over fifty countries
    • across six continents.

Understanding the Meaning

Let's start reading from the beginning:

The sentence tells us about a tech startup called DataFlow:

• It revolutionized mobile payment systems
• How? With its innovative encryption app
• When? In 2017

This is where we have the blank: after "(2017)"

Let's look at the choices:

• They're asking us to decide between:
  • (2017), and
  • (2017) and
  • (2017),
  • (2017) [nothing]

To see what works here, let's read the rest of the sentence and understand what it's saying!

The sentence continues:

• "the company quickly expanded operations to over fifty countries across six continents."

So this part tells us:

• The company (DataFlow) expanded operations
• Where? To over fifty countries across six continents

Now let's look at what we have overall:

FIRST PART: "The tech startup DataFlow revolutionized mobile payment systems with its innovative encryption app (2017)"

• This is a complete thought with:
  • Subject: The tech startup DataFlow
  • Action: revolutionized
  • What: mobile payment systems

SECOND PART: "the company quickly expanded operations to over fifty countries across six continents"

• This is also a complete thought with:
  • Subject: the company
  • Action: expanded
  • What: operations

What do we notice about the structure here?

• We have two complete thoughts that could each stand alone as sentences
• But they're closely related - both are about DataFlow's success
• The second follows from the first chronologically

When we want to connect two complete thoughts with "and," we need a comma before the "and."

So we need: (2017), and

The correct answer is Choice A.

GRAMMAR CONCEPT APPLIED

Connecting Two Complete Thoughts with a Comma and Coordinating Conjunction

When you have two complete thoughts (sentences that could stand alone, called independent clauses in grammar terms) and you want to connect them with a coordinating conjunction like "and," you must place a comma before that conjunction.

The pattern looks like this:

Complete Thought 1, and Complete Thought 2.

Examples:

• Example 1: The scientist conducted the experiment, and she published her findings.
  • Complete Thought 1: "The scientist conducted the experiment"
  • Comma + "and"
  • Complete Thought 2: "she published her findings"
• Example 2: The team scored three goals, but they still lost the match.
  • Complete Thought 1: "The team scored three goals"
  • Comma + "but"
  • Complete Thought 2: "they still lost the match"

In our question:

• Complete Thought 1: "The tech startup DataFlow revolutionized mobile payment systems with its innovative encryption app (2017)"
• Needs: Comma + "and"
• Complete Thought 2: "the company quickly expanded operations to over fifty countries across six continents"

Common coordinating conjunctions to remember: and, but, or, nor, for, yet, so

Important: Both thoughts must be complete (have their own subject and verb) to use this pattern. If one part can't stand alone as a sentence, you typically don't need the comma before "and."