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.

[EX Q]: Different units of measurement are more useful in some settings than in others. Which unit of measurement is most used when comparing distances within the solar system?  
 (A) the mile (B) the kilometer (C) the light year (D) the astronomical unit
[EX A]: D

[EX Q]: A shallow container of salt water is placed in sunlight for a day. Which is the most likely result?  
 (A) All of the mixture will evaporate. (B) The salt will keep the water from evaporating. (C) The salt will separate from the water and float at the top of the container. (D) Only the water will evaporate and the salt will remain in the container.
[EX A]: D

[EX Q]: Based on the organization of living things, tissues  
 (A) form systems. (B) are made of cells. (C) are made of organs. (D) do the work of cells.
[EX A]:
B