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:
The Grand Canyon is an example of  
 (A) erosion. (B) deposition. (C) an earthquake. (D) volcanic activity.
answer:
A


question:
A student conducts an investigation. In order to make a valid conclusion, she must  
 (A) have a testable hypothesis. (B) place the data in a graph. (C) use the best technology. (D) test multiple variables.
answer:
A


question:
Why is the light year often used to describe distances between objects in the universe?  
 (A) because of the way planets reflect light (B) because of the great number of bright stars (C) because of the way objects rotate and revolve (D) because of the large distance between objects in space
answer:

D