Cheerful Colors has budgeted 0.5 pounds of paraffin per batch of crayons, at a standard cost of $5 per pound. During October, laborers actually purchased and used 35,000 pounds of paraffin at a total cost of $210,000 when manufacturing 55,000 batches. What was Cheerful Color's direct materials efficiency variance for October?

A) $37,500 F

B) $45,000 F

C) $45,000 U

D) $37,500 U