Given the task definition and input, reply with output. You are given a science question (hard-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 student is investigating changes in the states of matter. The student fills a graduated cylinder with 50 milliliters of packed snow. The graduated cylinder has a mass of 50 grams when empty and 95 grams when filled with the snow. The packed snow changes to liquid water when the snow is put in a warm room. Which statement best describes this process?
(A) Cooling causes the snow to melt. (B) Cooling causes the snow to freeze. (C) Heating causes the snow to freeze. (D) Heating causes the snow to melt.
D