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.

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
D

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
D

The fur of an arctic fox turns from brown to white as winter approaches. This is an example of
(A) camouflage (B) hibernation (C) migration (D) movement
A