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]: What displays the movement of electrons from the base atoms? (A) venus (B) mercury (C) plasma star (D) pluto
[EX A]: C

[EX Q]: What becomes smoother through weathering? (A) rainbow (B) water (C) cat (D) pumice
[EX A]: D

[EX Q]: If a plant is in an environment with a lot of oxygen, and then oxygen levels very slightly drop, the plant will (A) understand (B) sour (C) calibrate (D) pray
[EX A]:
C