Davis Company expects the following results for the next accounting period :
Sales 180000$
Variable costs 108000$
Fixed cost 35000$
Expected production and sales in units 2500
The sales manager believes sales could be increased by 625 units of advertising expenditure were increased by 14000$. If advertising expenditures are increased and sales increase by 625 units, the effect on operating income will be a :
a. decrease of 4000$
b. decrease of 14000$
c. increase of 18000$
d. increase of 4000$