Office Supply Store Costs Are Expressed as a Function of the Unit

Multiple Choice

Office Supply store costs are expressed as a function of the unit sales of its two products: office chairs and task desks. Assume fixed costs are $9,000 per month and the variable costs are $60 per office chair and $125 per task desk.
What are Office Supply's estimated costs for the month if 100 office chairs and 52 task desks are sold?

A) $21,500
B) $25,000
C) $22,000
D) $20,500