B.

Subject is plural (Abraham Lincoln's simple writing style and enduring themes), so A and C are wrong

D is wrong -> 'as it was to ours'. It should be in present tense.

E is wrong -> 'as to ours' --> not a clause.

Nice job, GMAT0620 - and if that means you're taking the test on Monday, I think you're in good shape!

I love this question as a good example of a verb tense problem. Lincoln is clearly, at least to most of us, a historical figure, so "were" works for his attributes in the past tense, but because "ours" refers to us, now, we then have a need for the present-tense "are". Verb tense problems do not have to use the same tense throughout - in fact, in cases like these it's only logical to use different tenses. The correct answer will employ logical verb tenses for each action based upon the order in which they occur; it doesn't have to be the same throughout, even though I see people looking for that quite a bit on here...

I miss this question which is very hard and beautiful

Normally, we use DID when the specific time of past is indicated by time adverb and use HAVE DONE when the action is in the past but have no specific point of past time indicated or when the action is in the past and continue into the present.

but in this sentence, although there is no specific point of past time indicated by time adverb such as last century, we still use DID (were) because LOGIC DECIDES that the action is in the past totally.

EXPERT, PLEASE, HELP

I DO NOT KNOW HOW "HAVE DONE" IS USED TO REFER TO ACTION IN THE PAST. PLEASE, HELP

but this question maybe PROBLEMATIC because I see that even when the logic declares that total action is in the past, we still can use HAVE DONE to refer to this total past action when there is not time adverb.

THAT IS WHY I WISH EXPERT EXPLAIN MORE.