The correct option is D Temperature constraint for it to occur
The process of frost formation is the same as dew but with a few differences:
The physical state of water when dew forms is liquid and when frost forms, it is solid. The temperature at which the phenomenon occur also differ in that, the dew point, meaning the temperature at which condensation is taking place is above freezing point, the resultant will be liquid water droplets and if the dew point is at or below freezing temperature the resultant will be ice that is frost.