Pinnacle Corp. budgeted $270,290 of overhead cost for the current year. Actual overhead costs for the year were $222,380. Pinnacle's plantwide allocation base, machine hours, was budgeted at 45,740 hours. Actual machine hours were 56,430. A total of 96,170 units was budgeted to be produced and 98,000 units were actually produced. Pinnacle's plantwide factory overhead rate for the current year is: Oa. $2.31 per machine hour Ob. $5.91 per machine hour Oc. $4.86 per machine hour Od. $2.81 per machine hour