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 Q]: To which group does an animal belong if it lays eggs and has scales and gills?  
 (A) amphibian (B) bird (C) fish (D) reptile
[EX A]: C

[EX Q]: Which of the following climates has cold winters and hot summers?  
 (A) polar (B) subtropical (C) temperate (D) tropical
[EX A]: C

[EX Q]: Which of the following has been formed on the Asian continent by two continental plates that have been pressing together for millions of years?  
 (A) large fields of gravel (B) a tall mountain chain (C) large freshwater lakes linked by rivers (D) an uneven thickness of sedimentary layers
[EX A]:
B