One of these statements is the point of an argument, and the other three are support for that point. Click on the statement that is the point of the argument in this group.

a$.$ During the $1920$ s$,$ banks began offering the country's first home mortgages.

b$.$ Retail sellers of everything from cars to irons in the $1920$ s allowed customers to pay in installments.

c$.$ In the $1920$ s$,$ about $60$ percent of mortgages and $75$ percent of all radios were purchased on the installment plan.

d$.$ The use of installment credit became very popular with banks, retail sellers, and consumers during the $1920$ s$.$