Convection in the atmosphere is the process whereby air masses rise and fall, distributing heat and moisture over the planet.
a. true
b. false

I believe the correct answer would be true. Convection in the atmosphere is the process wherein the air masses rise and fall which results to the distribution of heat and moisture over the planet. It refers mainly to the atmospheric movements in the vertical direction so the rise and the fall. It is the result of the temperature difference of the lower air and the higher altitude air which results to the difference of the density of these air. In order to maintain equilibrium,  these masses of air would rise and fall accordingly depending on their differences affecting the average temperature of the Earth.