A "greenhouse" works because:?

Question

A. all greenhouses face south and into the maximum angle of solar energy

B. of the difference in the solar constant

C. the windows of the greenhouse only allow green light wavelengths to pass through

D. short wave lengths of energy pass through the glass but longer ones can't

Answer 1

Same as your car, or any window. When light from the sun passes through glass the wave length is altered so that it no longer can get back out, this forces the energy to stay put, building up heat.

Answer 2

D.  but they don't work so well facing north ;-)  unless you're south.