The recession of the early 1990s hit Southern California especially hard because:

a. The housing market crashed, and much of Los Angeles's wealth was tied up in real estate
b. The dotcom crash drove many Internet companies out of business
c. The end of the Cold War sparked a significant reduction in the defense spending going to Southern Californian aeronautics plants
d. Large numbers of undocumented immigrants returned to Mexico, leaving local businesses without enough workers It coincided with the worst drought of the 20th century, damaging the agricultural as well as the industrial economy