For each of the following service departments, select the activity base listd that is most appropriate for charging service expenses to responsible units. Service Department: a. Central Purchasing b. training c. Conferences d. Telecommunications e. Accounts Receivable f. Employee Travel g. Payroll Accounting h. Computer Support Activity Base: 1. Number of travel claims 2. Number of payroll checks 3. Number of sales invoices 4. Number of Purchase requisitions 5. Number of telephone lines 6. Number of employees trained 7. Number of computers 8. Number of conference attendees