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: The relationship between ticks and a dog can best be described as  
 (A) mutualism. (B) competition. (C) parasitism. (D) commensalism.

Answer: C


Question: 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.

Answer: C


Question: One student rubs a balloon against his hair several times. Another student passes a comb through her hair several times. The students place the comb near the balloon and observe that the comb repels the balloon. Which is the most likely reason the comb is able to repel the balloon?  
 (A) The balloon has a positive charge and the comb is neutral. (B) The balloon and the comb have the same electrical charge. (C) The balloon has a negative charge and the comb is neutral. (D) The balloon and the comb have opposite electrical charges.

Answer:
B