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 statement best describes how birth and death rates compare in a population at carrying capacity?  
 (A) The birth rate is greater than the death rate. (B) The birth rate is less than the death rate. (C) The birth rate is equal to the death rate. (D) The birth rate and the death rate are zero.
[A]: C


[Q]: People are developing electric cars that would replace gasoline-burning cars. One major advantage of the electric car is that it  
 (A) accelerates faster. (B) causes less pollution. (C) gives a smoother ride. (D) needs no battery.
[A]: B


[Q]: Which statement best explains why photosynthesis is the foundation of most food webs?  
 (A) Sunlight is the source of energy for nearly all ecosystems. (B) Most ecosystems are found on land instead of in water. (C) Carbon dioxide is more available than other gases. (D) The producers in all ecosystems are plants.
[A]:
A