Answer: The correct answer is conduction.
Step-by-step explanation:
There are three methods of heat transfer.
(1) Conduction: It is the method of the transfer of the heat directly. There is no transfer of the matter.
(2) Convection: It is the method of the transfer of the heat but not directly. There is transfer of the matter.
(3) Radiation: There is a transfer of heat from the solar energy.
In the given problem, a chef places sugar crystals in a cooking pan. He turns on the burner under the pan. In a few minutes, the sugar begins to melt.
Conduction process is responsible for transferring heat from the burner into the sugar. There will be no radiation and the convection process occur.
Therefore, the correct option is conduction.