Which of the following statements about margin of safety is false? O a. none of the given answers is false. O b. Margin of safety measures the difference between budgeted revenues and breakeven revenues. O c. If only the fixed costs increase but the number of units sold and unit selling price and unit variable cost are all constant, the margin of safety decreases. d. If the variable cost per unit decreases but the number of units sold, unit selling price and total fixed cost are all constant, the margin of safety decrease. . If only the variable cost per unit decreases but the number of units sold and unit selling price and fixed cost are all constant, the margin of safety increases