Magoosh Official Explanation:
Split #1: verb tense. The rise in cases of this disease is something that happened in the past, and may still be happening—that's unclear. Either the simple past "fueled" or present perfect "has fueled" could be correct—choices (A) & (B) & (D) & (E) have these. The past perfect would be correctly only if we wanted to establish contrast with another past event, but that doesn't make sense in this context: it changes the meaning
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