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: hydropower requires damming a river, Fact2: Many dams along rivers and creeks help prevent floods., Question: Hydropower requires what? (A) a hydraulic system (B) increases a body's strength (C) helping to prevent floods (D) Electric generators (E) flow of electrons (F) energy of moving objects (G) power stations (H) fissures of hot, acidic water
A:
C