A critical assumption about the behaviour of costs within the relevant range is (a) variable cost per unit and fixed cost per unit remain constant as sales volume increases. (b) variable cost per unit decreases and selling price per unit remains constant as sales volume decreases. (c) variable cost per unit remains constant and fixed cost per unit decreases as sales volume increases. (d) selling price per unit increases and fixed costs per unit decreases as sales volume decreases. The operating leverage of a business depends primarily upon (a) contribution margin. (b) level of sales. (c) level of fixed costs to total costs. (d) debt-to-equity ratio. The following sales budget has been prepared for Tenet Ltd. Month Total Sales January $15,000 February $16,000 March $18,000 April $14,000 On average, 50% of the total sales are cash sales which will be collected in the month of sale, and the remaining are credit sales. Collections from credit sales are 60% in the month following the sale, 40% two months following the sale. How much cash is expected to be collected in April? (a) $15,600. (b) $13,200. (c) $8,600. (d) $12,400