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: The number of fish in a lake suddenly increases. How will the increase most likely affect the lake?
(A) There will be less water in the lake. (B) More plants will grow in the lake. (C) More frogs will live in the lake. (D) There will be fewer insects in the lake.

Answer: D

Question: Diamonds are sometimes used as the tips of drill bits. Which physical property of a diamond MOST likely makes it a good cutting tool?
(A) its electrical properties (B) its thermal properties (C) its hardness (D) its density

Answer: C

Question: How does a human body get energy?
(A) Sunlight on the skin produces energy. (B) Water provides the majority of energy. (C) Food and oxygen combine to deliver energy. (D) Sleep provides energy stored at night for the next day.

Answer:
C