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 of the following most likely led to certain rocks having less friction? (A) a babbling brook (B) people (C) a light wind (D) money
Example Output: A

Example Input: When cutting down rain forests, it is important to keep in mind air quality. When too many trees are cut down in a given area, there may be decrease in the air's (A) quality (B) carbon dioxide (C) helium amounts (D) carbin dioyide levels
Example Output: A

Example Input: Sunlight is important for (A) communities (B) pollution (C) space (D) bats
Example Output:
A