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.

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

Which land feature is formed from erosion by waves?   
 (A) a sandbar (B) a sea cliff (C) a barrier reef (D) a barrier island
B

Which of the following is produced when sugar is digested in an animal cell?  
 (A) carbon dioxide. (B) chlorophyll. (C) oxygen. (D) sunlight.

A