HOT Competition (Instagram) 3 Sep/7:00AM: In the weeks after implement

Well, this sounds kinda crappy. South Korea “has seen” the number of cases decline. Awkward!

But remember: your ear is NOT your friend on GMAT SC. When I say that the sentence seems “awkward”, that’s just my opinion, and nobody cares about my opinion. The GMAT definitely doesn’t.

So are there real problems with (A)? I don’t see any.

The “-ing” word in the initial phrase (“...after implementing…”) jumps out at me, and the sentence only works if that phrase is followed by something -- or somebody -- that could plausibly implement a testing and contact-tracing program. We’re good, though: South Korea implemented that program.

The pronoun “that” at the end of the sentence also jumps out at me. “That” is a singular pronoun in this situation, and it would seem to refer to the nearest singular noun, “drop.” That works, since we now have “... a drop more than ten times as great as {the drop} in Asia as a whole over the same period…”

Perfectly logical, even if it doesn’t sound great. Keep (A).

Now we have a problem. What, exactly, does the singular pronoun “that” refer to here? It’s really hard to find a reasonable singular referent for “that.” I guess “the number of new COVID-19 cases”, but if we have to reach that far back to find the referent, the sentence isn’t as clear as it could be.

Let’s see if it works, anyway:

“South Korea has seen the number of new COVID-19 cases decline from 16 per million residents daily to less than 2 per million residents, more than ten times as great as {the number of new COVID-19 cases} in Asia as a whole…”

Think about that for a moment: we’re saying that “less than 2 (cases) per million residents” is more than 10 times GREATER than the number of new cases in the rest of Asia? That makes no sense in this context: the whole point of the sentence is that South Korea implemented “one of the world’s most aggressive testing and contact-tracing programs” -- and its cases are DRAMATICALLY higher than in the rest of Asia?

That can’t be right. (B) is out.

The pronoun “that” at the end of the sentence leads to the same logical problem as in (B). See above.

Also, the “-ing” word in the initial phrase (“...after implementing…”) is now a problem. Again, the sentence only works if that phrase is followed by something that could plausibly implement a testing and contact-tracing program. But it makes no sense to say that “the daily number of new COVID-19 cases” implemented anything.

So we have two good reasons to ditch (C).

(D) has exactly the same problem as (C): “... after implementing [testing and contact-tracing], the number of new daily COVID-19 cases…” makes no sense. “The number of cases” can’t possibly implement anything.

So (D) is out.

(E) has pretty much the same problem as (C) and (D): “... after implementing [testing and contact-tracing], South Korea’s daily number of new COVID-19 cases…” Don’t be fooled by the country name after the comma: it’s part of a possessive, so we’re still implying that the number of cases implemented a testing and contact-tracing program. Nonsense.

(E) is gone, and (A) is our answer.