Charles Wolfe purchased the following long$-$term investments at par during $2024$:

$$20,000$ general obligation bonds of Burlington County $($wholly tax$-$exempt$)$

$$10,000$ debentures of Arrow Corporation

Wolfe financed these purchases by obtaining a $$30,000$ loan from Union National Bank. For $2024,$ Wolfe made the following interest payments:

Union National Bank

$$3,600$

Qualified residence interest on home mortgage

$3,000$

Credit card interest

$500$

Wolfe$$s net investment income for the year was $$10,000.$ What amount can Wolfe utilize as interest expense in calculating itemized deductions for $2024?$

$$4,200$

$$6,600$

$$4,700$

$$7,100$