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").

[EX Q]: Once the grounds frost over and the air grows chilled (A) beaches are opened (B) humans go naked (C) birds lay eggs (D) roses die
[EX A]: D

[EX Q]: harming an animal species causes that animal 's population to do what? (A) explode (B) rise (C) plummet (D) burst
[EX A]: C

[EX Q]: changes in an environment cause plants to (A) morph for continuation (B) boogie (C) bake cakes (D) take long naps
[EX A]:
A