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:
A full moon is caused by (A) werewolves (B) moonlight (C) tides (D) orbiting

Ex Output:
D

Ex Input:
in order for a person's burger to make it successfully into the toilet, which of these must be functional? (A) the respiratory system (B) the digestive system (C) the circulatory system (D) the destructive system

Ex Output:
B

Ex Input:
A large source of heat can be seen in the (A) sky (B) cave (C) ocean (D) tree trunk

Ex Output:
A