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: Andre learned that plants survive through a process called photosynthesis. Which substance do plants produce during photosynthesis?  
 (A) minerals (B) nitrogen (C) soil (D) sugar

SOLUTION: D

PROBLEM: A scientist combines oxygen and hydrogen to form water. This combination illustrates that water is  
 (A) an atom. (B) an element. (C) a mixture. (D) a compound.

SOLUTION: D

PROBLEM: A structure that carries a single unit of hereditary information is a  
 (A) gene (B) tissue (C) sex cell (D) pedigree chart

SOLUTION:
A