The margin of safety is the difference between

A) contribution margin and net profit before tax.
B) budgeted contribution margin and actual contribution margin.
C) budgeted sales revenue and actual sales revenue.
D) budgeted sales revenue and break-even sales revenue.

The margin of safety is the difference between the budgeted or expected sales revenue and the break-even sales revenue. It represents the amount of sales that can be lost before the business starts incurring losses. Therefore, option D is the correct choice. Option A and B do not accurately represent the margin of safety, and option C is simply the variance between budgeted and actual sales revenue.