Instructions: 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").
Input: Which is true? (A) the equator has winter and summer at the same time (B) humans on the equator celebrate Christmas in May (C) the equator is always cold (D) humans on the equator can go either north or south to change season
Output:
D