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 land feature is most likely the result of a glacier?  
 (A) large, arid desert (B) deep, bowl-shaped lake (C) long crack in the ground (D) volcanic mountain range

Ex Output:
B


Ex Input:
Which is the best piece of equipment to determine the topography of the United States?  
 (A) radar (B) compass (C) satellite (D) radio

Ex Output:
C


Ex Input:
A student poured water into a plastic tray. The student then put the tray into the freezer. What property of the water changed as the water froze?  
 (A) The water became a gas. (B) The mass of water increased. (C) The water took a definite shape. (D) The flavor of the water changed.

Ex Output:

C