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.

[EX Q]: A cut to the skin is treated with antiseptic first to avoid
(A) an immune response. (B) a bacterial infection. (C) bruising of tissues. (D) an allergic reaction.
[EX A]: B

[EX Q]: Which of the following properties best describes a material's ability to resist scratching?
(A) weight (B) flexibility (C) length (D) hardness
[EX A]: D

[EX Q]: A girl signals her friend by shining a flashlight on a mirror. Her friend can see the signal because
(A) heat energy can be transferred from one object to another (B) mechanical energy can be transferred from one object to another (C) sound energy can be reflected from one object to another (D) light energy can be reflected from one object to another
[EX A]:
D