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 fact about water is an example of a chemical property?  
 (A) Water expands when it freezes. (B) The boiling point of water is 100ºC. (C) Water can separate into hydrogen and oxygen. (D) The density of water is greater than the density of ice.

Ex Output:
C


Ex Input:
Which function makes a plant cell different from an animal cell?  
 (A) ability to use energy (B) ability to absorb nutrients (C) ability to divide into two cells (D) ability to convert sunlight into energy

Ex Output:
D


Ex Input:
An atom can best be described as  
 (A) the smallest particle that has all the characteristics of a compound. (B) the smallest particle that has all the characteristics of an element. (C) a charged particle that is similar to a molecule. (D) a charged particle that is larger than a molecule.

Ex Output:

B