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 Input:
Fact1: Carbon may be stored in sedimentary rock for millions of years., Fact2: Limestone is a type of sedimentary rock., Question: What element can be stored in limestone for millions of years? (A) oxygen (B) Energy (C) matter (D) carbon (E) sodium (F) helium (G) rock salt (H) heat

Ex Output:
D

Ex Input:
Fact1: Echinoderms lack a centralized nervous system., Fact2: Sand dollars and sea biscuits are also echinoderms., Question: What lacks a centralized nervous system? (A) Damaged hearing (B) Humans (C) Horses (D) Sand dollars (E) insects (F) Chickens (G) Pesticides (H) barnacles

Ex Output:
D

Ex Input:
Fact1: Fertilization occurs when a sperm and an egg fuse to form a diploid zygote., Fact2: Sperm and eggs are cells known as gametes., Question: what fuses to form a diploid zygote during fertilization? (A) seeds (B) white (C) Flowers (D) pollen (E) potatoes (F) orchids (G) gametes (H) barnacles

Ex Output:
G