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]: Dirt is moved from one part of a forest to another, and travels across a field to get there. The movement is (A) caused by gusts (B) due to clouds (C) made by trees (D) because of litter
[EX A]: A

[EX Q]: What did some ancient societies use to reflect light? (A) wood (B) plants (C) clothing (D) rocks
[EX A]: D

[EX Q]: A waste product of human respiration (A) is a vital resource to pigs (B) is a vital resource to daffodils (C) is a vital resource to oceans (D) is a vital resource to bees
[EX A]:
B