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: A snail's shell provides the snail with
(A) food. (B) energy. (C) protection. (D) transportation.

SOLUTION: C

PROBLEM: What is the downward movement of water through pores and other spaces in soil due to the force of gravity?
(A) percolation (B) evaporation (C) precipitation (D) condensation

SOLUTION: A

PROBLEM: Sarah's class is learning about mixtures and solutions. Her teacher writes four statements on the board. Which statement best describes a mixture?
(A) Both substances mix evenly. (B) Both substances can evaporate. (C) One substance dissolves into another. (D) One substance can be separated from the other.

SOLUTION:
D