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: Which event can lead to the human caused change of an environment? (A) seasonal storms (B) annual flooding (C) natural woodland fires (D) clear cutting
Example Output: D

Example Input: A star produces light energy and heat because it has a variety of (A) moon rotation causing friction (B) light energy flowing to earth (C) reactions of nuclear form (D) global warming caused by co2
Example Output: C

Example Input: Corn and wheat are among the favorite foods of (A) humans (B) grizzly bears (C) fish (D) aliens
Example Output:
A