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: Hormones control many cell activities, so they are very important for homeostasis., Fact2: Many of the processes of homeostasis are mediated by hormones., Question: what does homeostasis mediate? (A) sweating (B) cardiac arrest (C) keeping the dog warm (D) cell activities (E) Plants growth (F) Animal survival (G) reproduction (H) photosynthesis
D