Gourley Clinic uses client-visits as its measure of activity. During August, the clinic budgeted for 3,200 client-visits, but its actual level of activity was 3,160 client-visits. The clinic has provided the following data concerning the formulas to be used in its budgeting: Fixed Variable element element per per month client-visit $39.90 Revenue.. Personnel expenses Medical supplies Occupancy expenses Administrative expenses Total expenses... $35,800 1,200 8,300 $10.70 7.90 1.50 0.30 $20.40 5,500 $50,800 The activity variance for personnel expenses in August would be closest to: Select one: O a. $428 F O b. $2,868 U c. $2,868 F 0 d. $428 U