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]: If a student gets a chemical splashed into an eye, what is the most appropriate first action to be taken?  
 (A) wipe it with a paper towel (B) call 911 for emergency services (C) have someone go get the school nurse (D) flush the eye with water at an eyewash station
[EX A]: D

[EX Q]: A girl found the skull of an animal. She did not know what the animal was but she was sure that it preyed on other animals for its food. What clue led to this conclusion?  
 (A) The eye sockets faced sideways. (B) The skull was much longer than it was wide. (C) There was a projecting ridge along the top of the skull. (D) Four of the teeth were long and pointed. (E) The jaws could move sideways as well as up and down.
[EX A]: D

[EX Q]: In a lab, a bacterial strain shows resistance to an antibiotic. The presence of the antibiotic allows an existing variant within the genetic code to help the bacteria survive. The resistance of bacteria due to an existing genetic variant can be best described as which process?  
 (A) natural selection (B) selective breeding (C) asexual reproduction (D) behavioral adaptation
[EX A]:
A