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: Evolution is a change in the characteristics of living things over time., Fact2: Evolution relies on random chance acts to cause mutations., Question: What causes changes in characteristics of living things over time? (A) mutations (B) science (C) parents (D) environment (E) light energy (F) news (G) alleles (H) animals
[EX A]: A

[EX Q]: Fact1: a breathing mask is used for keeping harmful particles from entering the respiratory system, Fact2: Oxygen enters the respiratory system through the mouth and the nose., Question: Breathing masks are used to keep harmful particles from entering the mouth and the what? (A) body (B) eyes (C) air (D) skin (E) gullet (F) nose (G) ears (H) lungs
[EX A]: F

[EX Q]: Fact1: Vertebrates are all chordates that have a backbone., Fact2: All chordates have jaws., Question: What do all vertebrates have? (A) fur and fat (B) sensory neurons (C) Veins and arteries. (D) four limbs (E) jaws and scales (F) a slimy coat (G) jaw and a backbone (H) feathers
[EX A]:
G