Explanation

Creating a filter: as we do the basic subject-verb check in the independent clause, "records" matches with "are," but we might ask whether "records" should be singular, since a decision about whether a certain item is a fossil is probably made item by item. That's not a conclusive consideration, however, so we can look for other differences in the answer choices

Logical proof: choice (B) gives us the grammatically singular "record" and "fossil," but it messes things up by using the plural pronoun "their" without a plural referent, so it's out. Choice (C) uses "their" as well in "their types," and it's meant to refer afterward to the grammatically singular "specimen." So (C) is out. Choices (D) and (E) are both free of "their." Choice (D) gives us the singular "record" we're looking for and is otherwise similar to (A). But then (E) reveals that both (A) and (D) are flawed, because it has the proper verb "determine." That verb should be grammatically plural, to correspond to "type of tissue and that of the external substance." We missed that basic defunct in our first scan of the question but found it soon enough. The correct answer is (E).