Waterproof Roofing Company has provided the following​ information:
Sales revenue ​$779,000
Variable costs ​506,000
Fixed costs ​216,000

Which of the following statements is​ true, if the sales volume increases by​ 10%?
(A) Contribution margin will increase by​ $77,900.
(B) Fixed expenses will increase by​ $21,600.
(C) Operating income will increase by​ $50,600.
(D) Operating income will increase by​ $27,300.