Assume that a company provided the following cost formulas for three of its expenses (where q refers to the number of hours worked): Rent (fixed) Supplies (variable) Utilities (mixed) $3,000 $4.009 $150 + $0.75q The company's planned level of activity was 2,000 hours and its actual level of activity was 1,900 hours. The actual amount of supplies expense for the period was $7,800. What is the activity variance for supplies expense? Multiple Choice $400 U $400 F $200 F $200 U