Here's a problem to solve: 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?

Among the 4 following options, which is the correct answer?

- 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.
 