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: 2000 years ago, this method would likely have brought sand from the coast to the desert (A) the pyramids often eroded, making their own sand (B) constant breezes over time (C) human automobiles transfer materials (D) the space shuttle moved sand great distances
Example Output: B

Example Input: Plants derive what from soil? (A) pollination and germination (B) life sustaining substances (C) roots and oxygen (D) oxygen and argon
Example Output:
B