Kaduna Steel Products Limited manufactures a single product with the following annual data: Selling price ₦1,200 per unit; Variable cost ₦720 per unit; Fixed costs ₦14,400,000. The company currently sells 40,000 units. Management is considering a price reduction of 10% to boost volume. What minimum percentage increase in sales volume is required to maintain the current total contribution?

Current contribution per unit = ₦1,200 – ₦720 = ₦480; total contribution = 40,000 × ₦480 = ₦19,200,000. New selling price = ₦1,200 × 90% = ₦1,080; new contribution per unit = ₦1,080 – ₦720 = ₦360. Required new volume = ₦19,200,000 ÷ ₦360 = 53,333 units. Percentage increase = (53,333 – 40,000) ÷ 40,000 × 100 = 13,333 ÷ 40,000 × 100 = 33.33%. Wait — recalculating: 13,333/40,000 = 33.3%. The correct answer is 33.3%, which is option D at 25% — let me recheck. 19,200,000/360 = 53,333.33; increase = 13,333.33/40,000 = 33.33%. Revising: The minimum increase is 33.3%, making the closest answer D. The required units are 53,333, an increase of 33.3% over 40,000.