You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

[EX Q]: At what time on a sunny day will the shadow of the school's flagpole be the shortest?
(A) sunrise (B) noon (C) mid-afternoon (D) sunset
[EX A]: B

[EX Q]: Melting, boiling, and freezing are examples of
(A) physical changes. (B) chemical changes. (C) magnetic changes. (D) electrical changes.
[EX A]: A

[EX Q]: Which of the following allows a cell to become specialized?
(A) location of the cell in the body (B) function of the cell in the body (C) different patterns of gene expression (D) different combinations of genes in the nucleus
[EX A]:
C