A cube of ice initially at 0° Celsius melts uniformly onto a table. The change in temperature from when it starts melting to when all the ice has been converted to water is:

  1. 0K
  2. 15K
  3. 273.15K
  4. 100K
  5. Not enough information

NOTE: This question is probably too simple for the GRE, but focuses on an important physics property that could be a crucial element of a GRE question.