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: a long tail can be used to move through water by an animal, Fact2: All thresher sharks have tail fins nearly as long as the rest of the body., Question: Fins nearly as long as what can be used to move through water? (A) most cephalopods (B) the rest of the body (C) animals with backbones (D) the eye of a needle (E) an organism's body (F) increases a body's strength (G) the body of water (H) the body of space
B