he following materials standards have been established for a particular product: Standard quantity per unit of output 4.2 meters Standard price $ 18.40 per meter The following data pertain to operations concerning the product for the last month: Actual materials purchased 7,200 meters Actual cost of materials purchased $ 138,600 Actual materials used in production 6,700 meters Actual output 1,550 units. What is the materials price variance for the month?

a. $3,658 U
b. $7,700 U
c. $11,770 U
d. $6,120 U