Assembly line workers at Thompson Manufacturing worked a total of 8,800 direct labor hours to produce 36,000 units. The standard for producing one unit is 15 minutes at a wage rate of $10. If the actual wage rate was $10.50 per direct labor hour, Thompson's direct labor efficiency variance rate is...

a) $2,000 F

b) $2,000 U

c) $2,100 F

d) $2,1000 U