The following data have been provided by Walsh Corporation: Budgeted production 7,400 units Standard machine-hours per unit 6.6 machine-hours Standard lubricants rate 3.50 per machine-hour Standard supplies rate $ 2.00 per machine-hour Actual production 7,600 units Actual machine-hours (total) 49,840 machine-hours Actual lubricants cost (total) $ 179,821 Actual supplies cost (total) $ 98,933 Lubricants and supplies are both elements of variable manufacturing overhead. The variable overhead rate variance for supplies is closest to: Select one: O a. $640 F O b. $747 F O c. $1,387 F O d. $1,387 U