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 thing which moves very little over quite a lot of time is a (A) pack of wolves (B) racing horses (C) falling rocks (D) giant ice brick

Ex Output:
D


Ex Input:
An echo is produced by what type of reflection of sound source? (A) Direct (B) Distant (C) Varied (D) Single

Ex Output:
D


Ex Input:
An example of a mixture is (A) light (B) a molecule (C) terra cotta (D) gold

Ex Output:

C