Which statement below most accurately describes the so-called "Greenhouse Effect" within Earth's atmosphere?
a. Some of the shortwave radiation reflected from land surfaces gets reflected again by clouds back toward the ground, thus warming the soil surface.
b. Warming of the land surface due to the construction of too many greenhouses.
c. Some of the shortwave radiation that would have otherwise warmed the land surface is reflected back to outerspace by clouds, thus cooling the Earth.
d. Some of the longwave radiation emitted from Earth back into the atmosphere is absorbed by atmospheric gases, which then heat up, and re-emit longwave radiation both outward into the atmosphere and back toward the land surface.