You are given a science question (hard-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]: Many states require vehicles to be examined and to meet safety and pollution standards. What impact might vehicle inspections have on the environment?
(A) The environment will not be polluted. (B) The environment will become more polluted. (C) Fewer pollutants will be released by vehicles. (D) Fewer pollutants will be produced by older vehicles.
[A]: C

[Q]: As part of a study, a scientist observed a number of different molecular changes in matter. Which of the following observations provides evidence of a physical change?
(A) using heat to burn a log in a fireplace (B) using light to produce sugar in plants (C) a cake that was baked from many ingredients (D) a bottle that was broken into many small pieces
[A]: D

[Q]: Which of the following is the best way to determine whether two people are related?
(A) Compare their blood types. (B) Compare their handwriting. (C) Compare their genes. (D) Compare their fingerprints.
[A]:
C