5. Nitrogen a holds the atmosphere around Earth.
b. is the second most common atmospheric gas.
c. is the most common atmospheric gas.
d. is the transfer of the energy between objects

c. is the most common atmospheric gas.

Explanation:

Nitrogen gas is the most abundant gas in the atmosphere. This gas is about 78% of total amount of gas within the atmosphere.

The earth's atmosphere is a mixture of many gases. Nitrogen is the most dominant of all the gases. Oxygen is about 21% and closely follows Nitrogen in terms of the volume it occupies. Several processes living and non-living utilizes nitrogen

Mantle convection is the process that drives plate tectonics. the theory of plate tectonics states that the crust is divided into plates that float on the semi molten mantle below. the circular motion of the magma as it slowly rises and falls or move though convection cells drags the plates along causing them to move. the heat source in the lamp would represent the earth's core. the core is the source of energy that drives convection in the mantle. the lava represents molten magma under the earth's surface. if the lava lamp had floating pieces they would move as the circular motion of the lava in the lamp as it rises and falls would move them along the surface. these floating pieces would represent pieces of the earth's crust. 

Ibelieve it is the 2nd answer, create gardens on all rooftops. let me know if this .