points KIMGIN SAS Manufacturing uses a standard costing system. The standard time to produce one unit is 4 hours, and normal production is 5,000 units monthly. Overhead costs wete estimated to be $250,000. The standard variable overhead rate is $5 per machine hour. During October, the following results were recorded: Units produced 006'y Units sold 009' Machine hours required $248,000 Actual overhead cost The combined fixed and variable overhead spending variance was: O a. $4,500 F O b. $2,000 Oc. $1,000 U Od. $4,500 U