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: The population of rabbits in an area increases. That could have been caused by (A) More predators have been moving into the area (B) The rabbits are becoming infertile (C) Hunters are trapping the rabbits (D) More precipitation falling lately
Example Output: D

Example Input: What are a source of fibers? (A) water (B) plantlife (C) rocks (D) air
Example Output: B

Example Input: Humidity is the amount of what vapor in the air? (A) wind (B) humidifier (C) cold (D) h2o
Example Output:
D