Coltrane Music manufactures musical instrument for sale to students and professionals. The information for one of Coltrane's most popular products, professional saxophones, follows: Product Saxophone Standard direct labor hours per saxophone 1.75 Standard direct labor rate per hour $30.00 Actual number of saxophones manufactured 690 Actual direct labor hours worked 900 Actual total direct labor cost $16,830 What is the labor rate variance for saxophones? O A. $10,170 unfavorable O B. $10,170 favorable OC. $7,797 favorable $7,797 unfavorable