Goldin Corporation currently pays its salesperson a flat salary of $5,000 per month and is considering paying him $20 per unit instead. Sales are currently 200 units per month. Goldin believes the compensation change will increase unit sales by 80%. The current contribution margin is $80 per unit. If the change is implemented, net operating income will:

a. decrease by $1,000b. decrease by $7,000c. increase by $7,000d. increase by $1,000