During $2024,$ John $($a self$-$employed management consultant$)$ went from Milwaukee to Hawaii on business. Preceding a five$-$day business meeting, he spent four days vacationing at the beach. Excluding the vacation costs, his expenses for the trip are:

Airfare$$3,200$Lodging$900$Meals$800$Entertainment$600$

Presuming no reimbursement, deductible expenses are:

a$.$ $$3,200.$

b$.$ $$4,500.$

c$.$ $$5,500.$

d$.$ $$3,900.$