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 $4.00 Standard variable overhead cost per unit $16.00 Actual variable overhead costs Actual DL hours Actual variable overhead cost per machine hour $17,625 2,350 $7.50 Actual tubs produced 900 What is the variable manufacturing overhead rate variance in March? O A. $5,000 favorable O B. $5,000 unfavorable OC. $8,225 unfavorable O D. $8,225 favorable