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: Bones support the body. What pulls and pushes on bones to move them?  
 (A) blood (B) nerves (C) muscles (D) skin

Answer: C


Question: The excessive use of nitrogen-based fertilizers causes runoff that increases the nitrogen content of lakes and bays. These nitrogen compounds directly affect the aquatic ecosystems by  
 (A) interfering with the water cycle. (B) decreasing the predator population. (C) increasing the rate of algae growth. (D) causing aquatic animals to grow larger.

Answer: C


Question: Salt and pepper are placed together in a container. When the container is shaken, the salt and pepper become a  
 (A) liquid. (B) mixture. (C) solution. (D) suspension.

Answer:
B