Vaughn Manufacturing planned to use 1 yard of plastic per unit budgeted at $96 a yard. However, the plastic actually cost $95 per yard. The company actually made 3600 units, although it had planned to make only 2800 units. Total yards used for production were 3660. How much is the total materials variance? A) $3660 F B) $7680 U C) $2100 U D) $76800 U