Given the task definition and input, reply with output. In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").

Fact1: Some mollusks are nearly microscopic., Fact2: Mollusks are the dominant invertebrate., Question: what are sometimes nearly microscopic? (A) humans (B) magnification (C) barnacles (D) Veins and arteries. (E) gastropod shells (F) invertebrates (G) orchids (H) the sun
F