The following is an extract of a cost report for Sally Furniture Services (SFS) for three months from March to May. Management considers the activities in the SFS business are within the relevant range for the purpose of cost estimation.

Month	No. of Customers	Service cost
March	500	$7,600
April	520	$7,960
May	480	$7,200

The furniture service cost is a:

Select one:

a. Semi-variable (or mixed) cost

b. Fixed cost

c. Variable cost

d. Step-fixed cost