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").

Fact1: telephones are used for communication by two people by transmitting sound, Fact2: And the sound of their voice becomes important as well., Question: What is transmitted with telephones? (A) voice (B) copper (C) waves (D) smell (E) cancer (F) energy (G) HIV (H) power
A

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

Fact1: a plant requires water to grow, Fact2: Ferns are vascular plants., Question: what requires water to grow? (A) density (B) ferns (C) gravity (D) rice (E) animals (F) Frogs (G) weathering (H) Oak

B