Wisseman Corporation is a shipping container refurbishment company that measures its output by the number of containers refurbished. The company has provided the following fixed and variable cost estimates that it uses for budgeting purposes. Fixed Element per Month Variable Element per Container Refurbished Revenue $ 5,300 Employee salaries and wages $ 55,100 $ 900 Refurbishing materials $ 600 Other expenses $ 41,200 When the company prepared its planning budget at the beginning of September, it assumed that 28 containers would have been refurbished. However, 26 containers were actually refurbished during September. The activity variance for total expenses for September would have been closest to: a. $400 F b. $400 U c. $3,000 U d. $3,000 F