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 Input:
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

Ex Output:
B


Ex Input:
You can work longer when (A) Autumn changes to Winter (B) spring changes to summer (C) tree leaves start falling (D) the first snow starts falling

Ex Output:
B


Ex Input:
What harmful phenomenon can cause atmospheric warming? (A) gasses with pollution (B) acid rain (C) nuclear war (D) melting ice caps

Ex Output:

A