Total production of 1,000 units of finished goods required 3,900 actual hours at $12 per hour. The standard is 4 hours per unit of finished goods, at a standard rate of $11 per hour. Which of the following statements is true? a. The labor rate variance is $3,900 favorable. b. The labor rate variance is $4,000 unfavorable. c. The labor efficiency variance is $1,100 favorable. d. The labor efficiency variance is $1,100 unfavorable. e. None of these.