Which of the following is not correct?

A. $${\text{Margin of Safety}} = \frac{{{\text{Profit}}}}{{\frac{{\text{P}}}{{\text{V}}}{\text{ratio}}}}$$

B. $$\frac{{\text{P}}}{{\text{V}}}{\text{ratio}} = \frac{{{\text{Change in contribution}}}}{{{\text{Change in sales}}}} \times 100$$

C. $${\text{Breakeven point in units}} = \frac{{{\text{Fixed Cost}}}}{{{\text{Contribution per unit}}}}$$

D. $${\text{Required sales to earn the desired profits}} = \frac{{{\text{Desired Profit}}}}{{\frac{{\text{P}}}{{\text{V}}}{\text{ratio}}}}$$

Answer: Option D