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.

[EX Q]: Eyeglasses help a nearsighted person see as a result of  
 (A) absorption. (B) diffraction. (C) reflection. (D) refraction.
[EX A]: D

[EX Q]: Which is a process that occurs during photosynthesis?  
 (A) Plants take in oxygen and release sugar. (B) Plants take in sugar and release minerals. (C) Plants take in minerals and release carbon dioxide. (D) Plants take in carbon dioxide and release oxygen.
[EX A]: D

[EX Q]: How would a drought most likely affect the plants of a grassy plain?  
 (A) There would be shorter plants. (B) They would have thicker stems. (C) There would be a greater variety. (D) They would have brighter flowers.
[EX A]:
A