is it unfavorable or favorable? this is how i think i got my answer (100-74)*130 = 3380

How do I solve this...how did you come to your answer

Applet Systems is a start-up company that makes connectors for high-speed Internet connections. The company has budgeted variable costs of $130 for each connector and fixed costs of $9000 per month. Applet's static budget predicted production and sales of 100 connectors in August, but the company actually produced and sold only 74 connectors at a total cost of $20,000. Applet's sales volume variance for total costs is

a) $3380 F.

b) $1380 F.

c) $3380 U

d) $1380 U.