Clinton's Engine Company manufactures part AT168 used in several of its engine models. Monthly unit production costs for 1,000 units are as follows: Direct materials $ 40 Direct labor 10 Variable overhead costs 30 Fixed overhead costs 20 Total $100

It is estimated that 10% of the fixed overhead costs assigned to AT168 will no longer be incurred if the company purchases AT168 from the outside supplier. Clinton's Engine Company has the option of purchasing the part from an outside supplier at $85 per unit.

1)If Clinton's Engine Company purchases 1,000 AT168 parts from the outside supplier per month, then its monthly operating income will Group of answer choices

a. decrease by $3,000

b. decrease by $85,000

c. increase by $2,000

d. increase by $80,000