How did Credit or Installment Buying contribute to later problems for many?

When people lost their jobs and could no longer make payment that were bought from the store or company that set up the installment plan, banks started to lose lots of money from unpaid installment plans. All of these unpayed loans contributed to the Great depression in 1929. Above is an ad for a typewriter on an installment plan.

Explanation:

letter a is the answer

the anwser is a) to prevent military conflict