Pinnacle Corp. budgeted $205,790 of overhead cost for the current year. Actual overhead costs for the year were $205,020. Pinnacle's plantwide allocation base, machine hours, was budgeted at 47,690 hours. Actual machine hours were 42,910. A total of 108,950 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. $4.32 per machine hour Ob. $1.88 per machine hour Oc. $1.89 per machine hour Od. $4.30 per machine hour