Voltaic Electronics uses a standard part in the manufacture of different types of radios. The total cost of producing $40,000$ parts is $$100,000,$ which includes fixed costs of $$40,000$ and variable costs of $$60,000.$ The company can buy the part from an outside supplier for $$2$ per unit and avoid $30\%$ of the fixed costs. Assume that the company can use the freed manufacturing space to make another product that can earn a profit of $$15,000.$ If Voltaic outsources, what will be the effect on operating income?

$$ A$.$ increase of $$15,000$

B$.$ increase of $$7,000$

C$.$ decrease of $$12,000$

D$.$ decrease of $$7,000$