Teacher: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").
Teacher: Now, understand the problem? Solve this instance: You wake up north of the equator, and you notice the sunrise happening earlier than yesterday and later than the day after, what day could it be (A) Feb. 21 (B) Dec. 21 (C) Sep. 31 (D) May 21
Student:
B