Explanation

Creating a filter: We read the prompt, and it passes the basic tests. So we move to the answer choices and will try to eliminate exhaustively, starting with (B).

Finding objective defects: Scanning, we can note that choices (A) through (C) begin one way, (D) and (E) another. Choice (D) uses an awkward "to be" construction, so we throw it out. Recall that, in the indirect statement of a belief, the best usage is usually "that," as we discussed in Recession Underway.Choice (E) has the same problem, in an even more garbled form. So we eliminate (D) and (E).

We are down to (A), (B), and (C), which differ in their verb tenses. What's the intended meaning of the sentence? It's that the development of present characteristics happened in the past. Choice (C) puts the characteristics in the past, so it's out. Choice (B) tries to get fancy without adding meaning. The use of "had" in "had developed" would have to refer to point before some other point in the past, but there is no such reference in the sentence to a moment in the past and a moment before that. The correct usage of past perfect (past tense with "had") is to refer to a point in the past prior to another, later point in the past. If there is no such later point, the use is incorrect. So (B) is out. The correct answer is (A).