Ring, Incorporated's income statement for the most recent month is given below. Total Store P Store Q Sales $600,000 $200,000 $400,000 Variable expenses 384.000 144,000 240.000 Contribution margin 216,000 56,000 160,000 Traceable fixed expenses 152.000 42.000 110.000 Segment margin 64,000 $14.000 $ 50.000 Common fixed expenses 34.000 Net operating income $30.000 If Store Q sales increase by $30,000 with no change in fixed expenses, the overall company net operating income should: a increase by $3,750 b. increase by $7,500 increase by $12,000 Od increase by $18,000