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: 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: Energy appears in many forms. What form of energy is lightning?
(A) electrical energy (B) mechanical energy (C) magnetic energy (D) sound energy

Answer: A

Question: Which material is the best natural resource to use for making water-resistant shoes?
(A) cotton (B) leather (C) plastic (D) wool

Answer:
B