Geary Co$.($lessor$)$ leased a machine to Dains Co$.($lessee$).$ Assume the lease payments were made on the basis that the residual value of $$15,000$ was guaranteed by Dains Co$.$ If$,$ at the end of the lease term, the fair value of the assets turns out to be $$7,800,$ which of the following entry is correct:$$

A$.$a debit entry of loss of $$7,200$ by Geary Co$.$

B$.$a debit entry of loss of $$7,200$ by Dains Co$.$

C$.$a debit entry of cash of $$7,200$ by Dains Co$.$

D$.$a credit entry of gain of $$7,200$ by Geary Co$.$