Definition: You are given a science question (hard-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.
Input: Four rods of equal thickness but made of different metals were tested with equal amounts of weight to see which was most flexible. Which of the following is the best way to report the results of this experiment?
(A) a list of each type of rod used (B) a sketch of each rod before testing (C) a table showing how much each rod weighed (D) a bar graph showing how much each rod bent
Output:
D