Correct Answer: Latent heat of fusion is the heat required to change a solid into a liquid at its melting point.
Step 1: Understand that 'latent heat' means heat energy that causes a change in state without changing temperature.
Step 2: Know that 'fusion' refers to the process of melting, where a solid turns into a liquid.
Step 3: Realize that the 'latent heat of fusion' is the specific amount of heat needed to change a solid into a liquid at the temperature where it melts.
