Question

How does convection occur in the troposphere?

The Sun’s rays heat Earth’s surface.
Warm air rises and cool air sinks.
The warm ground heats the air above it.
The Sun’s electromagnetic waves reflect off clouds.

Answer 1

Convection in the troposphere happens because the Sun heats Earth’s surface, the surface warms the air above it, and that warm air rises while cooler air sinks. So statements 1, 2 and 3 describe the process.

Statement 4 is not a cause of convection: clouds reflect some incoming solar radiation (which can reduce surface heating and thus inhibit convection), but reflection itself does not produce the rising/sinking air that is convection.