variable costs per unit and sales volume

variable costs per unit and sales volume

E plc operates a marginal costing system. For the forthcoming year, variable costs are budgeted to be 60% of sales value and fixed costs are budgeted to be 10% of sales value.
If E plc increases its selling prices by 10%, but if fixed costs, variable costs per unit and sales volume remain unchanged, the effect on E plc’s contribution would be:
A an decrease of 2%
B an increase of 5%
C an increase of 10%
D an increase of 25%
E an increase of 663%.