A snow removal company’s cost formula for its supplies cost…

A snоw remоvаl cоmpаny's cost formulа for its supplies cost is $1,790 per month plus $10 per driveway. For the month of January, the company planned for activity of 619 driveways, but the actual level of activity was 624 driveways. The actual supplies cost for the month was $8,500. The activity variance for supplies cost for the month would be closest to: