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: Echinoderms use pheromones to communicate with each other., Fact2: All echinoderms are deuterostomes ., Question: What use pheromones to communicate with each other? (A) passenger pigeons (B) honeybees (C) deuterostomes (D) Most plants (E) insects (F) animals (G) huddle together (H) orchids
[A]: C

[Q]: Fact1: cross-pollination increases genetic diversity, Fact2: Evolution requires genetic diversity., Question: What does evolution require? (A) Time and energy (B) Plant reproduction (C) cross-pollination (D) Reproduction (E) gene flow (F) coded genes (G) circulatory systems (H) animals with backbones
[A]: C

[Q]: Fact1: fluoride decreases tooth decay, Fact2: Tooth decay can be very painful, and can make teeth unsightly., Question: What can fluoride decrease the potential for? (A) precipitation (B) friendship (C) relationships (D) Tooth pain (E) Weight loss (F) movement (G) destruction (H) friction
[A]:
D