A radiation fog is likely to develop when there is

A.

gradual gain in heat by radiation on clear, clam nights

B.

rapid gain of humidity by insolation on calm days

C.

rapid loss of heat by radiation on clear, calm nights

D.

rapid gain of heat by radiation on clear calm days

E.

gradual loss of humidity by evaporation on calm days

Correct answer is C

No explanation has been provided for this answer.