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: Mammals have a layer of fat under the skin to help insulate the body., Fact2: Glass insulation keeps beverage warm for hours., Question: What keeps mammals warm? (A) evaporation (B) Animal fur (C) staying warm (D) sweating (E) They have thick fur (F) with their fur (G) a layer of fat (H) Veins and arteries.
[A]: G

[Q]: Fact1: Roundworms may be free-living or parasitic., Fact2: Roundworms make up the roundworm phylum, Nematoda., Question: What can the phylum Nematoda be? (A) dangerous (B) parasitic (C) horses (D) meiosis (E) more abundant (F) graptolites (G) homogenous (H) phytoplankton
[A]: B

[Q]: Fact1: plant reproduction often requires pollen, Fact2: Hay fever is caused by an allergy to pollens or moulds., Question: Hay fever is caused by (A) one celled organisms (B) bacteria (C) viruses (D) chemical messengers (E) carbon (F) heat energy (G) plant reproduction (H) single-celled organisms
[A]:
G