Which of the following equations calculates the operating income? Oa. Operating Income - (Unit Variable Cost x Units Sold) (Price x Units Sold) +Total Contribution Margi Ob. Operating Income - (Unit Variable Cost x Units Sold) -Fixed Cost c. Operating Income Sales - Fixed Cost Od. Operating Income Sales Total Contribution Margin Oe. Operating Income (Price x Units Sold) - (Unit Variable Cost x Units Sold) - Fixed Cost