Question

long wavelength (infrared) radiation... a cannot really be quantified. b is emitted by the earth because it is much cooler than the sun. c is not part of the earth-atmosphere energy balance.

Explanation:

• Option A: Infrared radiation can be quantified (e.g., via Planck's law), so A is wrong.
• Option B: Earth is cooler than Sun, emits long - wavelength (infrared) radiation, which is correct.
• Option C: Infrared radiation is part of Earth - Atmosphere Energy Balance (Earth emits it, atmosphere interacts), so C is wrong.

Answer:

B. is emitted by the Earth because it is much cooler than the Sun.