(9) An increase in production levels within the relevant range will result in (a) an increase in total variable costs (b) an increase in both total variable and total fixed costs (c) an increase in variable costs per unit (d) an increase in total fixed costs (10) What will be the effect of an increase in production volume on a mixed cost? (a) It will remain constant. (b) It will increase in total and increase per unit. (c) It will increase in total and decrease per unit. (d) It will increase in total but remain constant per unit