Final answer:
Santa Ana winds contribute to the (b) dry conditions in Southern California due to the rain shadow effect that occurs when prevailing winds lose moisture over mountain ranges.
Step-by-step explanation:
Santa Ana winds are notorious for exacerbating the dry situation in Southern California. This phenomenon occurs due to the rain shadow effect, where prevailing winds lose their moisture as they rise and cool over mountain ranges, resulting in very dry conditions on the leeward side.
Consequently, Santa Ana winds, which originate from higher elevations, descend towards the coast, heating up and drying out due to adiabatic compression, which further intensifies the dry conditions in the area.
The correct answer to the question is: Santa Ana winds especially exacerbate the (b) dry situation.