Detailed Instructions: 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: contact between rocks over long periods of time causes rocks to smooth, Fact2: Because of the big wave action, the rocks are very smooth., Question: What causes contact between rocks? (A) wind (B) heat (C) erosion (D) deltas (E) waves (F) motion (G) seasons (H) rivers
A:
E