aragon inc. budgeted $$45,000,000$ overhead in the current year and expected to use $500,000$ direct labour hours in its manufacturing activities. Direct labour hours is the cost driver for overhead allocation. If the actual overhead incurred was $$47,500$ and the actual direct labour hours were $500,000.$ The overhead will be

a$.$ over$-$allocated by $$2,500,000$

b$.$ Under$-$allocated by $$2,500,000$

c$.$ over$-$allocated by $$4,500,000$

d$.$ neither over$-$nor under$-$allocated