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]: the mantle is (A) a level of our planet (B) the planet closest to ours (C) a kind of rock found on Earth (D) the deepest part of our planet
[EX A]: A

[EX Q]: What does a tuna have that causes it to swim faster than a seahorse? (A) Lower body temperature (B) Bigger scales (C) Bigger fins (D) Thicker caudal fin
[EX A]: C

[EX Q]: Which example best shows the effect of vibration on matter? (A) a paper airplane (B) a harpsicord (C) a pillow (D) box of candy
[EX A]:
B