In and around the Tucson metropolitan area, there are a number of solar farms. There are solar farms near the town of Marana (northwest of Tucson), near Sahuarita (south of Tucson), near the town of _____ (also south of Tucson), on Davis-Monthan Air Force Base in Tucson itself, and in other locations around the metropolitan area.
a. Nogales
b. Green Valley
c. Rio Rico
d. Sierra Vista