In this task, you are given a multiple-choice question and you have to pick the correct option. Answer with option indexes (i.e., "A", "B", "C", and "D").

[Q]: if a chemical reaction occurs, it might have been triggered by which of these? (A) a person yelling at it (B) a person walking by it (C) a person looking at it intently (D) a person cranking up the room heater
[A]: D


[Q]: What does a seismograph measure? (A) the motion produced by underground collisions (B) the quaking of a man in fear (C) how strong the earth quakes beneath a stampeding herd (D) how strong waves can break plates
[A]: A


[Q]: Flowers make themselves attractive to hummingbirds with (A) nocturnal access (B) prickly thorns (C) dull, subdued colors (D) an optimal angle
[A]:
D