Answer:
Option D, Convection
Explanation:
The four main mechanisms that lift the air in the atmosphere and create clouds are a) Convection; b) Convergence; c) Updraft and d) Orographic Lifting
Radiation, conduction and water vapor are not responsible for creating lift in the atmosphere.
In convection, heat energy from sun raises the temperature of surface of the earth as it passes through the atmosphere. The air near the surface become less dense and hence starts rising thereby creating a lift.
Hence, option D is correct
