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: heat can change the state of matter, Fact2: Heat and temperature are the same thing., Question: What can change the state of matter? (A) temperature (B) color (C) a-a gradients (D) electricity (E) hypothyroidism (F) fossil fuels (G) global warming (H) flavor
[EX A]: A

[EX 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
[EX A]: B

[EX Q]: Fact1: Fingernails prevent injury by forming protective plates over the ends of the fingers., Fact2: People have fingernails., Question: who can prevent injury by forming protective plates over the ends of the fingers? (A) lamphreys (B) keratin (C) Cartilage (D) butterflies (E) ants (F) people (G) neurones (H) snakes
[EX A]:
F