2 Riverside Manufacturing designs and manufactures bathtubs for home and commercial applications. Riverside recorded the following data for its commercial bathtub production line during the month of March: Standard DL hours per tub Standard variable overhead rate per DL hour $6.50 Standard variable overhead cost per unit $13.00 Actual variable overhead costs Actual DL hours Actual variable overhead cost per machine hour $17,200 2,150 $8.00 Actual tubs produced 1,100 What is the variable manufacturing overhead rate variance in March? O A. $325 favorable O B. $325 unfavorable OC. $3,225 unfavorable OD. $3,225 favorable