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]: Which is the most important safety measure to follow when using an acid in a classroom laboratory?  
 (A) wearing protective clothing and goggles (B) keeping the window open (C) closing the door to the hall (D) using bright fluorescent lights
[EX A]: A

[EX Q]: Some types of bacteria can only live where oxygen is not present. These bacteria were well adapted to life on Earth over 2 billion years ago. Which of the following changes caused many of these bacteria to become extinct?  
 (A) the slow movement of tectonic plates (B) the varying temperatures of each season (C) an increase in volcanic activity under the oceans (D) an increase in the number of photosynthetic organisms
[EX A]: D

[EX Q]: Which would be the best method to use to dispose of cardboard boxes not utilized by a local grocery store?  
 (A) burn them once a month (B) send them to be dumped in a remote area (C) have them recycled for future paper products (D) put them into a dumpster with the rest of the trash
[EX A]:
C