Answering the Question As Fast As Possible

I surprisingly got to the answer D within 30 seconds. Let me show you how.

Step 1) Identify multiple commas—this is not a “laundry list” but rather several descriptive phrases. “Ultrathin” and “layered” are just words that describe “CONSTRUCTION.”

Step 2) The phrase “the same as the one making some butterflies shimmer” actually describes the “CONSTRUCTION of a butterfly’s wings“—NOT “wings” by itself.

Step 3) Cut the fluff:
“Scientists have recently discovered that the ultrathin, layered construction of a butterfly’s wings, the same as the one making some butterflies shimmer via the phenomenon of iridescence, are enabling the insect to control how much heat energy is absorbed by its wings and how much is reflected away. ”

Construction are enabling? Doesn’t make sense! So you know (A) is wrong.

It should be:

“Scientists have recently discovered that the ultrathin, layered construction of a butterfly’s wings, the same as the one making some butterflies shimmer via the phenomenon of iridescence, enables the insect to control how much heat energy is absorbed by its wings and how much is reflected away. ”

Step 4) Browse through the answer choices–but don’t read them from the beginning—look at the last few words: that also enables, enabling, also enables, also enable…

Which ones make sense? The “construction” of these guys (where “construction” is singular) ENABLES.
You must use “ENABLES”—so either (B) or (D).

Step 5) Note (B) has the extra word “that”—unnecessary. Also, it uses the word “which”—this implies the phrase describes “wings” when structurally the phrase really describes the “construction of the wings”–not the “wings.”

Therefore, (D) is the answer.

If you know how to strategically approach questions like these, you can most efficiently answer them in as little time as possible.