This question centers on subject-verb agreement (notice the “is” vs. “are” dichotomy at the end of each of the answer choices.) However, this is made more difficult by parenthetical comma phrases, which confuse some test-takers. Such phrases are not part of the subject of the sentence and can be completely ignored when evaluating for subject-verb agreement.
Answer choice A contains a compound subject (note the conjunction “and”.) This always forces the plural form of the verb. However, since A uses the singular form “is”, this answer can be eliminated.
Answer choices B, D, and E contain various parenthetical comma phrases after the subject. These phrases are not part of the subject. Since the subject (“Shoeless Joe Brown”) is singular, the verb should be singular as well. However, since B, D, and E use the plural form “are”, these answers can be eliminated.
The variation of the phrases “in addition to…”, “along with…”, and “as well as…” is actually a false alarm. There is no substantive difference between these phrases, but test-takers are often trapped trying to evaluate such synonymous phrases. If you are not sure if a change in wording is grammatically significant, look for other leverage words or phrases that might provide additional ways of eliminating answers. (I call this tactic “Pick Your Battles”!)
Answer choice C is the correct answer. It correctly matches the singular subject (“Shoeless Joe Brown”) with the singular verb form (“is”.) Some test-takers mistakenly eliminate answer choice C because of the parenthetical comma phrase in between the subject and the verb. However, this phrase is a trap. Because it is not part of the subject of the sentence, it doesn’t affect the verb form.