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:
A student examines a new watch design. The watch has a small solar cell on its face. The main function of the solar cell is to  
 (A) reduce the cost of the watch. (B) provide an energy source for the watch. (C) make the watch more attractive. (D) stop the watch from speeding up.
answer:
B


question:
Which could be a possible way to prevent wildlife species from becoming endangered?  
 (A) drinking less water (B) establishing more habitats (C) cutting down more forests (D) stopping underground coal mining
answer:
B


question:
Which statement describes a characteristic of a gas that has a significant effect on the climates of both Earth and Venus?  
 (A) Nitrogen is chemically inert. (B) Sodium vapor reflects solar energy. (C) Carbon dioxide traps solar energy. (D) Argon is unable to react with water.
answer:

C