Starforce Avionics makes aircraft instrumentation. Its basic navigation radio requires $$60$ in variable costs and $$2,000$ per month in fixed costs. Further processing the radio, to enhance its functionality, will require an additional $$25$ per unit of variable costs but no change to the fixed costs. The marketing manager believes that the company would be able to increase the sales price from $$260$ to $$280.$ If Starforce decides to further process the product, operating income would:

A$.$ increase by $$25$ per unit

B$.$ remain the same

C$.$ decrease by $$5$ per unit

D$.$ increase by $$85$ per unit