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").

[Q]: As a soccer ball goes flying through the air, the person watching it knows that the reason is because (A) everything is aerial (B) exerting occurred (C) balls are birds (D) soccer takes wing
[A]: B

[Q]: A person who wants to visit a desert will be sure to pack more (A) winter boots (B) thermal underwear (C) tan shorts (D) snowsuits
[A]: C

[Q]: What is a source of oxygen through photosynthesis? (A) lakes (B) car engines (C) sunflowers (D) people
[A]:
C