Hey daagh,
Nice work on the explanation, but I'll suggest that you do them in the alternate order. Subject-verb agreement should be a pretty convenient decision point for you, particularly when the difference is between the last word of each answer choice:
makes
make
makes
make
makes
You know that you're making a singular/plural decision with "make(s" here, so let's look at what is doing the "making". It has to be the sagacity and insight - a compound, and therefore plural, subject. Your other options as nouns are:
Economic judgment (which is part of a modifier leading with "of", so it's not the subject)
Bill Clinton (but his other verb, "showed", is past-tense so it wouldn't match with "makes", and the compound noun is structured with "that" to be the new subject)
So we know that with a plural subject we need "make" to be the verb, and that gets us right down to B and D.
Now we have:
"considered one of the greatest"
"regarded like one of the greatest..."
"like" means "similar to", so the logic of sentence D is incorrect - he's not regarded "similar to" a great President or "as if he were" a great President, he's regarded as, or considered, a great President. Now that we're done with the major S-V error, the more minor idiomatic feel/meaning error is hopefully easier to spot.