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 incompleteness of the fossil record results primarily from which phenomenon?
(A) the frequency and irregular timing of organism speciations (B) the metamorphosis of most sedimentary rock by heat and pressure (C) the geologically rapid cycling of crust material back into the mantle (D) the rarity with which organic remains are exposed to fossil-forming conditions

SOLUTION: D

PROBLEM: What is the function of skin on the human body?
(A) Skin has pores that help the body sense odor. (B) Skin protects the body from harmful substances. (C) Skin brings oxygen directly into the body's bloodstream.

SOLUTION: B

PROBLEM: A water hose was left running on a pile of dirt. What feature of stream erosion was most likely being demonstrated?
(A) the rate of water flow in a stream (B) the time it takes for deposition to occur along a stream (C) how layers of rocks and soil are formed along a stream (D) how water shapes a stream over time

SOLUTION:
D