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: Streams may start with runoff or water seeping out of a spring., Fact2: Most water comes from precipitation., Question: What do most streams start with? (A) swamp vegetation (B) heat produced (C) loose dirt (D) Decibels (E) Veins and arteries. (F) matter vibrating (G) visible energy (H) precipitation
[EX A]: H

[EX Q]: Fact1: Ancestors of hagfish are thought to have been the earliest vertebrates., Fact2: Property of ancestors and forefathers can only be legally inherited by sons., Question: Forefathers of what kind of fish are thought to be the earliest vertebrates? (A) hagfish (B) Pelycosaur (C) fish (D) angiosperm (E) adult (F) Therapsids (G) marine (H) aquatic
[EX A]: A

[EX Q]: Fact1: Phytoplankton are bacteria and algae that use sunlight to make food., Fact2: Most copepods feed on phytoplankton., Question: what do most copepods feed on? (A) animals (B) bacteria and algae (C) density (D) body water (E) scarce resources (F) salt and water. (G) an organism's body (H) oxygen
[EX A]:
B