please help on 29 and 30

29. Which of the following is not a characteristic of an investment center? a. The center's manager has control over revenues and costs only. b. The subunit has responsibility for generating revenues, controlling costs, and generating a return on assets. c. The subunit can be evaluated using residual income. d. The subunit can be evaluated by comparing it to other investment centers. 30. Starg Corporation, a retailer, plans to sell 14,000 units of Product X during the month of August. If the company has 7,000 units on hand at the start of the month, and plans to have 7.500 units on hand at the end of the month, how many units of Product X must be purchased from the supplier during the month? a. 21,500 b. 14,500 c. 13,500 d. 14,000