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 thermal insulator slows the transfer of heat, Fact2: Heat transfer fluids, such as antifreeze, protect the solar collector from freezing in cold weather., Question: What protects things from freezing in cold weather? (A) exoskeleton (B) thermal insulators (C) thick filling (D) a hydraulic system (E) Animal fur (F) layers of skin (G) layers of fat (H) deep water
B