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: The greatest amount of diversity can be found among which type of organism?
(A) plants (B) animals (C) bacteria (D) fungi

SOLUTION: C

PROBLEM: A population of plants growing on an island consisted of two varieties, one with thorns and the other without. Over a period of many years, the variety with thorns gradually disappeared. Which process most likely brought about this change in the plant population?
(A) gene flow (B) genetic drift (C) natural selection (D) random mutation

SOLUTION: C

PROBLEM: A puddle of water on a concrete driveway will disappear after a few hours during a sunny day. Where does the water go as it disappears?
(A) It goes into the air. (B) Animals drink it. (C) It soaks into the concrete. (D) It becomes a different substance.

SOLUTION:
A