William Butler Yeats' stirring poem Meditations in Time of

As we often see in GMAT sentence correction, we have a long descriptive phrase to ignore. We should read the sentence to ourselves as:

(I moved the underline one word to the right, since none of the answers, including (A), include "for".)

Now that the extraneous material is gone, it's easier to analyze the sentence. The original sounds pretty good, so let's scan the choices looking for differences.

The first thing we likely see is "number" vs "amount". We use number for countables and amounts for non-countables. Can you count "interpretations"? Sure - you could have 1, 2, 3 4 or 500 interpretations. Since interpretations are countable, we need "number": eliminate C, D and E.

Now we scan A and B for a difference and we note "little" vs "less". Do little and less mean the same thing? No - little is simply a quantifier and less implies a comparison. Are we comparing the amount of debate about Yeats' meaning to some other amount of debate? Nope - therefore "less" changes the meaning of the sentence to something nonsensical and we can eliminate B.

Our original instincts prove correct - choose A!

As a small aside, even if you just notice that "less" changes the meaning of the sentence, that's good reason to choose A over B. The correct answer to a SC question will always reflect the author's intended meaning and the original sentence is our best guide to the author's intentions.