Q: 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: breathing is when a gill converts from oxygen in water into oxygen in blood, Fact2: Most fish breathe through gills., Question: How do fish get oxygen? (A) muscles (B) gills (C) water (D) dorsal fin (E) eyes (F) skin (G) rivers (H) blood
A:
B