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.

Ex Input:
Which of these is not a benefit of microorganisms?  
 (A) They release nutrients in soil. (B) They help make antibiotics. (C) They cause food to spoil. (D) They break down waste.

Ex Output:
C


Ex Input:
Which of these objects will most likely float in water?  
 (A) glass marble (B) steel ball (C) hard rubber ball (D) table tennis ball

Ex Output:
D


Ex Input:
As part of a study, a scientist observed a number of different molecular changes in matter. Which of the following observations provides evidence of a physical change?  
 (A) using heat to burn a log in a fireplace (B) using light to produce sugar in plants (C) a cake that was baked from many ingredients (D) a bottle that was broken into many small pieces

Ex Output:

D