What is the principal source of thermal energy for the layer of air closest to Earth's surface?

Geothermal energy that travels up from the Earth's core.

The sun's rays, which directly heat air molecules as they travel.

Energy transferred from the Earth's sun-warmed surface.

Heat generated by friction from fast-moving global wind currents.

Why is the air temperature generally warmer near the ground and cooler higher up in the troposphere?

The sun's rays are more concentrated and powerful near the ground.

The atmosphere is mainly heated from below by the warmed surface of the Earth.

Cooler, denser air naturally sinks to the ground, pushing any warm air upwards.

Air pressure is higher at the surface, which compresses the air and increases its temperature.

Solar energy -> heats air -> heats ground

Geothermal energy -> heats ground -> heats air

Solar energy -> heats ground -> heats air

Solar energy -> reflects off clouds -> heats air

It has no effect on the air after the sun has set.

It continues to warm the air from below.

It cools the air by drawing heat out of it.

It causes the air to become more humid.

Solar energy heats the surface directly and the atmosphere indirectly.

Solar energy heats the atmosphere directly and the surface indirectly.

Solar energy heats both the surface and the atmosphere directly and equally.

Solar energy is mostly trapped by the atmosphere and never reaches the surface.