A product's standard cost card specifies that a unit of the product requires 4 direct labor-hours. During September, 3,350 units were made, which was 150 units less than budgeted. The total budgeted direct labor cost for September was $117,600. The direct labor cost incurred during September was $111,850 and 13,450 direct labor-hours were worked. The labor rate variance for the month was:

a) $5750 F

b) $1130 U

c) $5750 U

d) $1130 F