When Using the Reciprocal Method to Allocate Support Costs, Which

When using the reciprocal method to allocate support costs, which of the following equations represents the algebraic expression for the total costs of a Custodial Department (C) that includes not only $120,000 of direct costs but also 15% of the Maintenance Departments (M) cost?

A) C = $120,000 + (.15 ÷ M) .
B) C = ($120,000 x .15) + M.
C) C = $120,000 - (.15 x M) .
D) C = $120,000 + (.15 x M) .