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: One important use of coal is to produce energy for homes. Coal can be burned and converted to  
 (A) wind energy. (B) nuclear energy. (C) electrical energy. (D) solar energy.

Answer: C


Question: What change would occur if Earth's rate of rotation significantly increased?  
 (A) The year would be shorter. (B) The year would be longer. (C) The day would be shorter. (D) The day would be longer.

Answer: C


Question: How do the waxy stem covering and needle-shaped leaves improve the ability of a cactus to survive in the desert?  
 (A) They make the plant appetizing to small desert animals. (B) They prevent the loss of oxygen through photosynthesis. (C) They reduce the loss of water from the plant to the air. (D) They provide the storage space for different types of minerals.

Answer:
C