A firm has two production departments: Department X and Department Y.

Both production departments are supported by two service departments: Department A (i.e. the power department) and Department B (i.e. the maintenance department). Departments A and B also consume service from one another.

The work done by Departments A and B is summarized in the table below (work by Department A is in kilowatt-hours; work by Department B is in labor hours).

Work provided By	A	B	X	Y
Department A	0	50	125	75
Department B	250	0	50	200

Costs of Department A are $200,000, and costs for Department B are $80,000.

What percentage of maintenance department labor hours are consumed by the power department?

A) 20%

B) 50%

C) 100%

D) 80%