Summerlin Company budgeted 4,000 pounds of material costing $5.00 per pound to produce 2,000 units. The company actually used 4,500 pounds that cost $5.10 per pound to produce 2,000 units. What is the direct materials quantity variance?

a. $400 unfavorable.
b. $450 unfavorable.
c. $2,500 unfavorable.
d. $2,550 unfavorable.
e. $2,950 unfavorable.