Question

what is one way that housing changed in the postwar period?
suburban developments began to spring up when builders applied assembly-line techniques to homes.
people began moving out of the cities and into rural areas.
people began saving so that they could pay cash for their houses.
apartments were built as rapidly as possible in order to compete for the best tenants.

Explanation:

In the postwar period (notably the US post-WWII), assembly-line mass production techniques were adopted by home builders. This allowed for fast, affordable construction of identical homes, which led to the rapid growth of suburban developments. The other options are incorrect: people moved to suburbs, not rural areas; most used mortgages rather than cash; the focus was on single-family suburban homes, not apartment competition for tenants.

Answer:

A. Suburban developments began to spring up when builders applied assembly-line techniques to homes.