TASK DEFINITION: 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.
PROBLEM: Earth is composed of layers of material with different properties. Which of the following is most likely to be in constant motion?
(A) core (B) mantle (C) oceanic crust (D) continental crust

SOLUTION: B

PROBLEM: Which two life processes occur in both plants and humans?
(A) growing and reproducing (B) germinating and making food (C) growing and making food (D) germinating and reproducing

SOLUTION: A

PROBLEM: Extinction of a species is most likely to occur as a result of
(A) evolution (B) migration (C) selective breeding (D) environmental changes

SOLUTION:
D