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.

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


[Q]: Which of these are scientific classifications for galaxies in the universe?  
 (A) dust, gas, ice (B) small, medium, large (C) spiral, elliptical, irregular (D) red giant, white dwarf, supernova
[A]: C


[Q]: Weather stations built in urban areas can be influenced by the human-made structures that surround these stations. Some of these weather stations used to determine mean temperatures in the United States have had the validity of the data questioned. Which human-produced effect could these urban weather stations be measuring?   
 (A) heat island (B) rain shadow (C) land breeze (D) cold front
[A]:
A