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]: Riding a two wheeled human powered vehicle is good for the environment because (A) it runs without fuel (B) it helps people stay in shape (C) they are cheaper to maintain (D) they are more fun to drive
[EX A]: A

[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]: Wind energy is (A) unreal (B) careless (C) re-useable (D) noneffective
[EX A]:
C