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:
Unlike trees in the forest or a pond full of fish, metal is only available until (A) it is depleted for good (B) it is found on catfish scales (C) it becomes necessary to conduct electricity long distances (D) it is used to make diamond rings

Ex Output:
A


Ex Input:
Every 1440 minutes (A) the moon is full (B) there's a lunar eclipse (C) a new year starts (D) the sun sets in the west

Ex Output:
D


Ex Input:
Which of the following is correct? (A) The earth's strong gravitational pull causes a waxing gibbous to form (B) astrology causes a waxing gibbous to form (C) star maps cause a waxing gibbous to form (D) government satellites cause a waxing gibbous to form

Ex Output:

A