TASK DEFINITION: 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.
PROBLEM: When oxygen combines with hydrogen, which substance is formed?  
 (A) water (B) vinegar (C) hydrochloric acid (D) hydrogen dioxide

SOLUTION: A

PROBLEM: Many sports stadiums use grass, but some use fake grass called artificial turf. Artificial turf is made of fibers that look like real grass. In which way is this technology most likely beneficial?  
 (A) It uses less water. (B) It produces more heat. (C) It releases less moisture. (D) It absorbs more carbon dioxide.

SOLUTION: A

PROBLEM: Which structure surrounds and protects an animal cell?  
 (A) Nucleus (B) Vacuole (C) Cytoplasm (D) Cell membrane

SOLUTION:
D