Firm A is a successful firm and thus the going concern is applied. The credit policy is net $30$ days. Assuming the price per unit is $$50,$ the variable cost per unit is $$30,$ the probability of default is $10\%,$ and the monthly required return is $2\%,$ what is the NPV of granting credit?$$19\mathrm{.}610-$$$8\mathrm{.}590-$$$14\mathrm{.}710$ $$8\mathrm{.}59($ $$14\mathrm{.}71$