instruction:
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.
question:
Which action involving a pulley system requires the least amount of force?  
 (A) using several pulleys together instead of a single pulley (B) using a fixed pulley instead of a moveable pulley (C) pulling a long rope instead of a short rope (D) pulling a rope up instead of down
answer:
A


question:
Which property of air does a barometer measure?  
 (A) speed (B) pressure (C) humidity (D) temperature
answer:
B


question:
Which example best illustrates kinetic energy?  
 (A) a light bulb that is turned on (B) a car that is parked on top of a hill (C) a comet that is flying through space (D) a battery that is connected to a circuit
answer:

C