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").
Q: Fact1: Roundworms reproduce sexually., Fact2: Roundworms make up the roundworm phylum, Nematoda., Question: What reproduces sexually? (A) viruses (B) humans (C) insects (D) orchids (E) the Sun (F) Nematoda (G) ferns (H) plants
A:
F