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 Q]: The fur of some animals becomes thicker in the winter and is shed in the spring. These observations show how animals  
 (A) respond to changes in the environment (B) move from place to place to survive (C) store fat for the winter (D) compete with other animals for food
[EX A]: A

[EX Q]: Which of the following has the least momentum?  
 (A) a 0.5 kg mass with a 1000 m/s velocity (B) a 1 kg mass with a 100 m/s velocity (C) a 10 kg mass with an 11 m/s velocity (D) a 100 kg mass with a 2 m/s velocity
[EX A]: B

[EX Q]: Which statement is an example of an inherited trait in a living thing?  
 (A) A child learns to ride a bicycle. (B) A cat has a kitten with a broken leg. (C) A white dog has a puppy with white fur. (D) A person has a scar from a burn.
[EX A]:
C