Falcon Co$.$ produces a single product. Its normal selling price is $$25$ per unit. The variable costs are $$15$ per unit. Fixed costs are $$19,500$ for a normal production run of $5,000$ units per month. Falcon received a request for a special order that would not interfere with normal sales. The order was for $1,59$ units with a special price of $$21$ per unit. Falcon has the capacity to handle the special order, and for this order, a variable selling cost of $$2$ per unit wou eliminated. If the order is accepted, the differential effect on profit would be $a(n)$

a$.$ increase of $$10,176$

b$.$ decrease of $$7,632$

c$.$ increase of $$16,536$

d$.$ increase of $$12,720$