People aren't going to be able to answer this without the passage.
I didn't really understand your question.
Answer: Convection defines the heat transfer by air or water. It is the process by which heat is transferred from a hotter body to a colder body.
Explanation:
Examples of convection are: Steam rising from a coffee mug, smoke rising from campfire, heater blowing warm air.
The warmer air moves up and the colder air sinks in or down. This is how the convection works.
The heat from coffee moves through the steam particles into the air. Another example is heated air blows from the blower. The smoke rising from fire carries warm air to the upside and colder air to downside.
The answer to this question will be D
