Final answer:
The margin of safety is calculated by subtracting the breakeven point from the actual sales volume and dividing by the actual sales volume. In this case, the margin of safety is 200 units.
Step-by-step explanation:
The margin of safety is a measure of how far sales can drop before a business starts to experience a loss. It is calculated by subtracting the breakeven point (where total revenue equals total cost) from the actual sales volume and dividing by the actual sales volume. In this case, the business sold 600 units of the product and the breakeven point can be calculated as follows:
Breakeven point = Total fixed costs / Selling price per unit - Variable cost per unit
Breakeven point = £2,400 / (£10 - £4) = 400 units
Margin of safety = (Actual sales volume - Breakeven point) / Actual sales volume
Margin of safety = (600 - 400) / 600 = 200 / 600 = 1/3 = 33.3%
Therefore, the margin of safety is 200 units (option D).