Bamba Corporation's cost formula for its selling and administrative expense is $47, 900 per month plus $52 per unit. For the month of April, the company planned for activity of 6,000 units, but the actual level of activity was 6, 040 units. The actual selling and administrative expense for the month was $364, 490. The activity variance for selling and administrative expense in April would be closest to: $4, 590 F $2, 080 F $4, 590 U $2, 080 U