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.

A rubber band will make a sound when it is  
 (A) vibrated. (B) stretched. (C) cut into pieces. (D) shot across a room.
A

Which characteristic of sound makes it possible for bats to fly in the dark without hitting any objects?  
 (A) refraction (B) reflection (C) conduction (D) amplification
B

Peristalsis helps move nutrients through parts of the body by using wavelike contractions. In which system is the function used?  
 (A) circulatory (B) digestive (C) endocrine (D) nervous

B