Hello Everyone!
Let's tackle this question, one thing at a time, and narrow it down to the correct answer quickly! To begin, let's take a quick scan over the options, highlighting any major differences between the options in orange:
Many stock traders in the United States have set out to become global investors, convinced that limiting their investments to the U.S. stock market, even though it is certainly home to the stocks of some of the world's great corporations, restricted their gains.
A. even though it is certainly
B. which, while it is certainly
C. despite that that market is certainly
D. which, though certainly
E. although, certainly as
After a quick scan over the options and the original sentence, it looks like we're dealing with MODIFIERS. The best way to tackle modifiers is to plug each option into the sentence and check for a few things:
1. Are the modifiers clearly referring to the right antecedents?
2. Are there any unclear or vague pronouns?
3. Does the sentence still work with the modifier taken out?
Let's take a look at each option with the underlined portion plugged in and eliminate any that don't work:
A. Many stock traders in the United States have set out to become global investors, convinced that limiting their investments to the U.S. stock market, even though it is certainly home to the stocks of some of the world's great corporations, restricted their gains.
This is CORRECT! There aren't any issues with how this modifier is worded, and it's clear that the pronoun "it" is referring to the United States stock market.
B. Many stock traders in the United States have set out to become global investors, convinced that limiting their investments to the U.S. stock market, which, [spoiler]while it is certainly home to the stocks of some of the world's great corporations,[/spoiler] restricted their gains.
If we read what's left over, it doesn't really work. Parenthetical statements - statements wedged between commas - are considered non-essential clauses, which means they can be removed from the sentence without changing meaning or creating grammatical errors. If we take out the modifier here and leave the "which," it sounds like the clause was cut off mid-thought. Therefore, we can eliminate this option because the word "which" chops in half the modifier "convinced that limiting their investments to the U.S. stock market restricted their gains."
C. Many stock traders in the United States have set out to become global investors, convinced that limiting their investments to the U.S. stock market, despite that that market is certainly home to the stocks of some of the world's great corporations, restricted their gains.
This is INCORRECT because the construction is confusing and overly wordy. The modifier and the phrase after it ("restricted their gains") both sound like verb phrases, which is confusing. It should be clear to readers that "limiting their investments to the U.S. stock market" is how they restricted their gains, NOT that the market has some of the world's biggest corporations. The way this is worded makes it hard to follow what the writer is trying to say.
D. Many stock traders in the United States have set out to become global investors, convinced that limiting their investments to the U.S. stock market, which, [spoiler]though certainly home to the stocks of some of the world's great corporations,[/spoiler] restricted their gains.
This option has the same problem as option B - it chops up the modifier into two parts, instead of leaving it as one statement when you remove the parenthetical phrase.
E. Many stock traders in the United States have set out to become global investors, convinced that limiting their investments to the U.S. stock market, although, [spoiler]certainly as home to the stocks of some of the world's great corporations,[/spoiler] restricted their gains.
Again, this option splits the modifier into two parts, which doesn't work.
There you have it - option A was the correct choice all along! It's the only one that uses clear wording and correct modifiers to convey meaning.
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