If heat is flowing from a table to a block of ice moving across the table, which of the following must be true?
a. the table is rough and there is friction between the table and ice. b. the ice is cooler than the table. c. the ice is changing phase. d. all three are possible, but none is absolutely necessary.

The ice is cooler than the table.

Explanation:

The difference in temperature is a necessary condition for the transfer of heat between two bodies.

Here if the heat is being transferred from the table to an ice block this means that the temperature of the table is greater than the ice which drives the heat energy from the table to the ice block and the heat will continue to flow until they both attain a common temperature.

However,

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.