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: extreme heat and pressure change rock into metamorphic rock, Fact2: Slate is a metamorphic rock., Question: What rock is formed by extreme heat and pressure (A) erosion (B) crust (C) calcite (D) Slate (E) dead (F) forces (G) fibrous (H) complex
[A]: D

[Q]: Fact1: Male dogs use pheromones in urine to mark their territory., Fact2: Pheromones are natural aphrodisiacs., Question: What do male dogs use in urine to mark their territory? (A) Natural aphrodisiacs (B) competing for resources (C) Tails (D) Urine cleaner (E) Something coming from a gland (F) Chemical energy (G) an area swollen with pus (H) Chew toys
[A]:
A