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").

[EX Q]: Fact1: fat is used to keep animals warm, Fact2: Humans are a new type of animal., Question: what uses fat to keep warm? (A) Lobsters (B) bacon (C) humans (D) pigeons (E) insects (F) omnivores (G) plants (H) bears
[EX A]: C

[EX Q]: Fact1: nuclear reactions in stars causes stars to produce light, Fact2: And, of course, the Sun is a star., Question: What in the sun causes the sun to produce light? (A) energy of moving objects (B) hydrogen and oxygen (C) heat energy (D) water (E) solar rays (F) rotation (G) nuclear reactions (H) kinetic energy
[EX A]: G

[EX Q]: Fact1: Lymphocytes are the key cells involved in the immune response., Fact2: Allergies are an immune system response., Question: Lymphocytes are a key cell involved in what type of reaction? (A) Final Symphonic movement (B) illness (C) positive (D) fever (E) allergic (F) autologous transplant (G) allogenic stem cell transplant (H) sweating
[EX A]:
E