instruction:
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.
question:
When the cardboard cone of a radio speaker vibrates, it produces a sound in the air around it. The cone produces this sound by transferring which of the following to the air around it?  
 (A) heat (B) current (C) wave motion (D) magnetic force
answer:
C


question:
A scanning electron microscope is best suited for observing  
 (A) diffraction of light. (B) tectonic features on planets. (C) the surfaces of small objects. (D) topographical features on the ocean floor.
answer:
C


question:
Which of the following is an example of a physical change but not a chemical change?  
 (A) A log gives off heat and light as it burns. (B) A tree stores energy from the Sun in its fruit. (C) A penny lost in the grass slowly changes color. (D) A water pipe freezes and cracks on a cold night.
answer:

D