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: An object such as a hammer weighs less on the Moon than on Earth. This is because the Moon has a  
 (A) thinner atmosphere than Earth. (B) smaller diameter than Earth. (C) stronger magnetic field than Earth. (D) lower mass than Earth.

SOLUTION: D

PROBLEM: The body is made up of many systems that interact with one another. For example, the skeletal system and the muscular system work together to help the body move. Which system works with the respiratory system to distribute oxygen to the body?  
 (A) muscular system (B) digestive system (C) lymphatic system (D) circulatory system

SOLUTION: D

PROBLEM: Which two activities use most of the water used in an average U.S. household?  
 (A) flushing toilets and washing clothes (B) washing clothes and using sink faucets (C) using sink faucets and showering (D) showering and flushing toilets

SOLUTION:
A