Changes affecting profit via contribution margin Steps:

• Profit = (Selling price - Marginal cost) × Sales volume - Fixed costs.
• Change 1 increases marginal cost, reducing contribution margin per unit and total profit.
• Change 2 decreases fixed costs, increasing total profit directly.
• Change 3 increases sales volume, boosting total contribution and profit if above break-even.
• Change 4 decreases selling price, reducing contribution margin per unit and total profit.

Why B is correct:

• Changes 1 and 4 both shrink the contribution margin ((P - MC) decreases), making profit harder to achieve per the CVP formula.

Why the others are wrong:

• A includes 2, which lowers costs and raises profit.
• C includes 2, which lowers costs and raises profit.
• D includes 3, which raises revenue and profit.

Final answer: B