Phoenix, Arizona experiences large annual temperature ranges, but scant rainfall year-round with a slight maximum in July and August. What would be the cause of this bump in precipitation?

a. The Intertropical Convergence Zone (ITCZ) migrates to its most southern position in the summer months.
b. Southerly winds sweep over the region brining afternoon showers and thunderstorms from the summer monsoon.
c. The cool summer nights causes warm, moist air to condense producing frequent flash flood events.
d. Warm, moist air rises along the windward side of the Rocky Mountains producing frequent rain bands.