TASK DEFINITION: You are given a science question (hard-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: Which of these has the greatest capacity for storing thermal energy from the Sun?
(A) air (B) land (C) oceans (D) plants

SOLUTION: C

PROBLEM: Two layers of sedimentary rock are exposed on the side of a hill. Only one of the layers has fossils. The lack of fossils in one layer of sedimentary rock is most likely due to
(A) changing environments. (B) volcanic activity. (C) changing rates of erosion. (D) evaporation of sea water.

SOLUTION: A

PROBLEM: Beavers build their homes in ponds and streams. Which characteristic is least critical to building homes in an aquatic environment?
(A) waterproof fur (B) webbed hind feet (C) large, sharp teeth (D) flat, wide tail

SOLUTION:
C