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").

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

Example Input: Sleet is made out of water that is (A) vapor (B) hot (C) liquid (D) cold
Example Output: D

Example Input: Toasting bread makes it (A) smaller (B) longer (C) wider (D) harder
Example Output:
D