Which Best Describes Mountain and Valley Breezes

Multiple Choice

Which best describes mountain and valley breezes?

A) These are characterized by warmer air descending mountain slopes during the day and valley air ascending the mountain slopes at night.
B) These are caused by valley floors heating more quickly than valley slopes during the day and cooling more rapidly at night.
C) These involve warm air rising upslope during the day,creating an area of low pressure; at night it is reversed with a low pressure area forming on the valley floor.
D) These are secondary wind systems.