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: Sponges are filter feeders., Fact2: Since mussels are filter-feeders, they clean water as they feed., Question: What cleans the water as it feeds? (A) ecosystems (B) sharks (C) cats (D) fish (E) arachnids (F) horses (G) lamphreys (H) sponges
A:
H