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.

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

Which of these will best separate a saltwater solution?  
 (A) using a paper filtering system (B) using chromatography (C) allowing the salt to settle (D) allowing the water to evaporate
D

A scientist finds the bones of a dinosaur. What could help the scientist determine the approximate age of the dinosaur bones?  
 (A) the birds living in the area of the bones (B) the weather conditions in the area of the bones (C) the kinds of trees living in the area of the bones (D) the index fossils in the area of the bones

D