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 Input:
Which characteristic of frogs is an adaptation to living in water?  
 (A) strong legs (B) webbed feet (C) dull colors (D) moist skin

Ex Output:
B


Ex Input:
Oxygen reacts with iron to produce rust and with hydrogen to produce water. Which statement describes both reactions?  
 (A) A different mixture is formed in each case. (B) A different solution is formed in each case. (C) Both a change of state and of elements is involved. (D) New molecules are formed but the same elements exist.

Ex Output:
D


Ex Input:
Perry studies the ways in which animals are adapted for survival. Which is a behavioral adaptation that helps the organism to survive?  
 (A) the long neck on a giraffe (B) the webbed feet on a duck (C) a bear hibernating in winter (D) a flower attracting a honeybee

Ex Output:

C