The correct answer is C.
The margin of safety is the amount of sales revenue that a company can lose before it starts to incur a loss. It is calculated by dividing the break-even sales by the actual sales.
The break-even sales is the amount of sales revenue that a company needs to generate in order to cover its fixed costs. It is calculated by dividing the fixed costs by the contribution margin.
The contribution margin is the amount of sales revenue that a company keeps after paying for its variable costs. It is calculated by subtracting the variable costs from the sales revenue.
Therefore, the margin of safety is calculated by dividing the break-even sales by the actual sales, which is option C.
Option A is incorrect because it divides the profit by the P/V ratio. The P/V ratio is the contribution margin ratio, which is the percentage of sales revenue that a company keeps after paying for its variable costs. The profit is the amount of money that a company makes after paying for all of its costs, including its fixed costs. Therefore, option A does not measure the margin of safety.
Option B is incorrect because it divides the fixed costs by the contribution margin. The fixed costs are the costs that a company incurs regardless of the amount of sales revenue that it generates. The contribution margin is the amount of sales revenue that a company keeps after paying for its variable costs. Therefore, option B does not measure the margin of safety.
Option D is incorrect because it divides the profit by the sales revenue. The profit is the amount of money that a company makes after paying for all of its costs, including its fixed costs. The sales revenue is the total amount of money that a company makes from selling its products or services. Therefore, option D does not measure the margin of safety.