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]: Humans contribute to environmental pollution (A) by purchasing products made from recycled products (B) by switching to energy efficient appliances (C) by leaving behind refuse on public beaches (D) by frequently recycling paper and plastic
[EX A]: C

[EX Q]: Why animal may use a rock as shelter (A) Centipede (B) Dolphin (C) Seagull (D) Dog
[EX A]: A

[EX Q]: What happens when someone on top of a bicycle starts pushing it's peddles in a circular motion? (A) the bike wheelies (B) the bike turns (C) the bike brakes (D) the bike accelerates
[EX A]:
D