Ruby Company follows activity-based budgeting. From the information given below, calculate the total activity cost of the company. Activity description Activity driver Cost per unit of driver Amount of driver Processing mail Number of clients $120 $75 Paying bills Number of bills $ 2.5 $10,000 Investigating Number of new hires $110 $75 Writing reports Number of clients $150 $75 a. $52,500 b. $52,800 c. $53,500 d. $53,200