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.

Q: Which would most likely be the characteristic of an object with a small volume and large mass?  
 (A) high density (B) low pressure (C) low viscosity (D) high temperature

A: A
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Q: When nitrogen-rich runoff from farms enters a nearby farm, it causes abundant growth of algal mat on the pond surface. As a result, underwater plants in the pond begin to die. Identify the limiting factor that is most responsible for causing the underwater plants to die.  
 (A) oxygen (B) sunlight (C) nitrogen (D) carbon dioxide

A: B
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Q: How do plants affect their environment?  
 (A) Plants clean the soil. (B) Plants make sunlight brighter. (C) Plants make food used by other organisms. (D) Plants create water

A:
C
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