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.

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.
D

Which of the following is most consistent with the modern theory of evolution?  
 (A) Parents pass their physical traits to their offspring; those offspring with traits that help them survive in the environment are able to reproduce. (B) Parents change their physical traits in order to survive in the environment, then those parental traits are passed to their offspring. (C) Life on this planet came from another planet far out in space. (D) Living organisms have not changed for hundreds of millions of years.
A

Which question can be answered by scientific experimentation and observation?  
 (A) Are dogs better pets than cats? (B) How many stars are in the universe? (C) In what type of light will a plant grow best? (D) How many organisms have lived on Earth?

C