A study has been conducted to determine if one of the departments in MSU Company should be discontinued. The contribution margin in the department is $50,000 per year. Fixed expenses charged to the department are $65,000 per year. It is estimated that $40,000 of these fixed expenses could be eliminated if the department is discontinued. These data indicate that if the department is discontinued, MSU's overall net operating income would:

a. decrease by $25,000 per year.

b. increase by $25,000 per year.

c. decrease by $10,000 per year.

d. increase by $10,000 per year.