Marge incurred a $$35,000$ expense. If her marginal tax rate is $20\%,$ which of the following statements is true?

$$ if only $$10,000$ of the expense is deductible, Marge's after$-$tax cost is $$25,000.$

if the expense is nondeductible, Marge's after$-$tax cost is zero, and if the expense is deductible Marge's after$-$tax cost is $$28,000.$

if the expense is deductible, Marge's after$-$tax cost is $$28,000.$

if the expense is nondeductible, Marge's after$-$tax cost is zero.