A profit-maximising monopolist faces a demand function where total revenue at 10 units of output is ₦800 and at 11 units is ₦847. If the marginal cost of the 11th unit is ₦50, the monopolist should

Marginal revenue from the 11th unit = ₦847 − ₦800 = ₦47. Since MR (₦47) is less than MC (₦50), the firm should NOT produce the 11th unit — wait, re-checking: MR = ₦47 < MC = ₦50, so the firm should reduce output. However, the question asks about the decision at 10 units looking forward; at the 11th unit MR (₦47) < MC (₦50), so the profit-maximising output is 10 units. The correct interpretation is that the firm should NOT increase to 11 units; it should stay at 10 units. Re-evaluating the answer: D is incorrect; the firm should maintain 10 units. The correct answer is C — maintain output at 10 units because moving to 11 units would mean MR < MC, reducing profit.