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: When light is bounced off a mirror, the light is  
 (A) reflected. (B) refracted. (C) absorbed. (D) diffracted.

SOLUTION: A

PROBLEM: After a star runs out of most of its hydrogen fuel, it becomes hotter and more luminous. What stage does this represent in the life cycle of a star?  
 (A) quasar (B) protostar (C) red giant (D) white dwarf

SOLUTION: C

PROBLEM: How would the Sun appear to an astronaut on Pluto compared with how it looks from Earth?    
 (A) The Sun would appear larger and brighter. (B) The Sun would appear smaller and brighter. (C) The Sun would appear larger and dimmer. (D) The Sun would appear smaller and dimmer.

SOLUTION:
D