Branch Corporation uses a standard cost system to account for the costs of its one product. Variable overhead is applied using direct labor hours. Standards allowed for each unit are 1,3 hours of labor at a varlable overhead rate of $21. During November, Branch Corporation produced 2.850 units. Payroll totaled $98,180 for 5,090 hours worked. Variable overhead incurred totaled $122,185. Required: a. Calculate the variable overhead rate variance. Note: Round your intermediate calculations to two decimals and final answers to nearest whole dollar. Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i.e., zero variance). b. Caiculate the variable overhead efficiency variance. Note: Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i.e., zero variance). c. Calculate the variable overhead spending variance. Note: Round your intermediate calculations to two decimals and final answers to nearest whole dollar. Indicate the effect of variance by selecting "Favorable", "Unfavorable", or "None" for no effect (i.e., zero variance)