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.

Which physical structure would best help a bear to survive a winter in New York State?  
 (A) big ears (B) black nose (C) thick fur (D) brown eyes
C

Often organisms seem similar in their outward appearances. For example, a porpoise and a shark seem closely related, but they are not. Such similarity is the result of  
 (A) convergent evolution. (B) adaptive radiation. (C) artificial selection. (D) genetic equilibrium.
A

Humans have a body system that helps to deliver nutrients and hormones, remove excess wastes, and exchange gases. Which body system is most responsible for these functions?  
 (A) excretory (B) circulatory (C) respiratory (D) reproductive

B