E. Sales required for desired after-tax operating income: Let's denote the desired after-tax operating income as X. X = (Operating Income + Desired Income) / (1 - Tax Rate) $45,000 = (Operating Income + $45,000) / (1 - 0.25) Solving for Operating Income: Operating Income + $45,000 = $45,000 / (1 - 0.25) Operating Income + $45,000 = $60,000 Operating Income = $60,000 - $45,000 = $15,000 Now, let's find the sales required to achieve this operating income: Sales = (Operating Income + Fixed Costs) / Contribution Margin Ratio Sales = ($15,000 + $120,000) / 0.25 Sales = $540,000