Harris, Inc., has just completed job nos. 78 and 79, which were similar in terms of complexity, production processes, and units manufactured. Job no. 78 was manufactured by Joe Barton who earns $14 per hour, whereas job no. 79 was completed by Susan Franklin who earns $20 per hour. If Joe and Susan are equally efficient, would the company be better off using direct labor cost or direct labor hours as the cost driver in its predetermined overhead rate? Briefly explain