Concept:Rain formed by strong surface heating and rising air currents in tropical regions.
Explanation:In the tropics, the sun intensely heats the ground and the air above it.
This warm, moist air becomes lighter and rises quickly in convection currents.
As the air climbs higher, it expands, cools, and reaches its dew point.
Water vapour then condenses into cumulonimbus clouds, producing heavy rainfall with thunder and lightning.
This process defines convectional rainfall, which is the most common rainfall type in tropical areas.
The other types—fog, relief rain, and frontal rain—are less frequent or localised within the tropics.
Answer:D. convectional