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.
--------
Question: A scientific guess about the cause and effect of an event is called
(A) a variable. (B) a theory. (C) a hypothesis. (D) an observation.

Answer: C

Question: Solids, liquids, and gases are all different states of which of the following?
(A) mass (B) matter (C) weight (D) volume

Answer: B

Question: Which tool should a carpenter use to measure the length of a wooden board?
(A) balance (B) meter stick (C) thermometer (D) graduated cylinder

Answer:
B