please help on 21 and 23 thanks

As a practical matter, to which account are variance accounts with insignificant halances usually closed? a. Manufacturing Overhead b. Work in Process Inventory c. Finished Goods Inventory d. Cost of Goods Sold 22. The following standards for variable manufacturing overhead have been established for a company that makes only one product: hours 5.8 Standard hours per unit of output Standard variable overhead rate $12.20 per hour The following data pertain to operations for the last month: 2,575 $32,035 hours Actual hours Actual total variable manufacturing loverhead cost 150 units Actual output What is the variable overhead efficiency variance for the month? a. $21,421 U b. $20,801 U c. $620 F d. $10,614 F