14.10 Gimball Grace Ltd manufactures a single model of electric fan heater. Each heater sells for £21. Variable costs of manufacture are £7.50. Fixed costs of the business are estimated at £54,000 for the 20X9 financial year. The net profit of the business in 20X8 was £36,500, and the directors hope to increase that by 10% in 20X9. How many fan heaters will they have to sell to reach their target net profit (to the nearest whole unit)?

a) 6,974 units

b) 4,000 units

c) 6,704 units

d) 7,374 units