Two hours direct labor costs at 90 are included in the unit cost of a product. In a given period, 200 units were manufactured and for 390 hours worked, a total amount of 39,000 was paid. In this period, the following applies for direct labor costs: Efficiency volume variance and Price variance:

a) 900 favorable and 3,900 unfavorable

b) 900 favorable and 4,000 unfavorable

c) 1,000 favorable and 4,000 unfavorable

d) 1,000 favorable and 3,900 unfavorable