The standard costs and actual costs for factory overhead for the manufacture of 2,800 units of actual production are as follows:

Standard Costs

Fixed overhead (based on 10,000 hours)……………………..3 hours per unit @ $0.78 per hour

Variable overhead…………………………....…………………..3 hours per unit @ $1.91 per hour

Actual Costs

Total variable cost, $17,800

Total fixed cost, $8,100

The variable factory overhead controllable variance is

a. $1,756 favorable

b. $1,756 unfavorable

c. $1,405 favorable

d. $0