A comprehensive investigation into the causes of the 1929 stock market crash was published by economists at Princeton University in...

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:

• A comprehensive investigation
  • into the causes of the 1929 stock market crash
• was published
  • by economists at Princeton University
  • in 1963

Sentence 2:

• [?] study
• challenges
  • several long-held assumptions
  • about financial market behavior
  • and regulatory effectiveness

Understanding the Meaning

Let's start with the first sentence:

'A comprehensive investigation into the causes of the 1929 stock market crash'

• This is telling us about a thorough study/investigation
• It focused on figuring out what caused the famous 1929 stock market crash

'was published by economists at Princeton University in 1963.'

• This investigation was published
• Who published it? Economists at Princeton
• When? 1963

So the first sentence gives us: A detailed investigation about the 1929 crash was published by Princeton economists in 1963.

Now we move to the second sentence, and here's where we need to fill in the blank:

'_____ study challenges several long-held assumptions...'

Let's look at our choices:

1. These (plural)
2. Those (plural)
3. This (singular)
4. Several (plural quantifier)

What do we need here?

• The word needs to work with "study" which is singular
• It should refer back to the investigation we just read about in the first sentence
• "Investigation" and "study" mean essentially the same thing in this context - the second sentence is talking about the same investigation mentioned in the first sentence

Since "study" is singular (we're talking about one specific study - the investigation mentioned in sentence 1), we need a singular word to go with it.

Looking at our choices:

• "These study" - doesn't work (plural with singular)
• "Those study" - doesn't work (plural with singular)
• "This study" - works! (singular with singular)
• "Several study" - doesn't work (would need "studies" plural)

So we need This - it's singular and refers back to the investigation from the previous sentence.

Now let's read the complete second sentence:

'This study challenges several long-held assumptions about financial market behavior and regulatory effectiveness.'

The complete picture is:

• The investigation/study that was published in 1963
• challenges (goes against) several assumptions that people had held for a long time
• These assumptions were about how financial markets work and how effective regulations are

What do we notice?

• We're using a word to point back to something mentioned in the previous sentence
• That word needs to match in number with the noun that follows it
• "Study" is singular, so we need the singular form "this"

The correct answer is C. This

GRAMMAR CONCEPT APPLIED

Demonstrative Pronouns Must Match the Number of the Noun

When you use words like "this," "that," "these," or "those" to point to something (these are called demonstrative pronouns in grammar terms), they must match whether the following noun is singular or plural:

Singular demonstratives (for one thing):

• This + singular noun: "this study," "this book," "this finding"
• That + singular noun: "that study," "that book," "that finding"

Plural demonstratives (for more than one):

• These + plural noun: "these studies," "these books," "these findings"
• Those + plural noun: "those studies," "those books," "those findings"

In this question:

• The noun is "study" (singular)
• We need a singular demonstrative
• "This" correctly pairs with "study"
• "This" also appropriately refers back to the investigation mentioned in the previous sentence

Common mistake pattern:
Students sometimes choose plural demonstratives when they're thinking about multiple aspects of something, but you must always match the actual noun that follows. Here, even though the study discusses multiple assumptions, the word "study" itself is singular, so we need "this."