John Smith, a factory worker at an automobile plant in the city Detrigan, makes $25 per hour. His dad, Larry Smith who retired from a plant in the same city ten years back, was earning an average of $10 per hour at the time of retirement. Looking at the CPI, John concludes that a factory worker's purchasing power is lower now compared to ten years ago. Larry, however, does not agree that purchasing power has fallen. According to him, this conclusion cannot be drawn from such limited data. Which of the following, if true, would weaken Larry's claim that the purchasing power of an average factory worker has not fallen? A. The labor market in Detrigan has become more competitive over the last ten years. B. The level of unemployment in Detrigan is currently low compared to historical averages. C. Price levels have been increasing mainly due to the increase in the average disposable income in Detrigan. D. The total number of hours worked by an average factory worker has fallen over the years. E. A study shows that the average worker can buy a car with 45 weeks of his pay compared to 50 weeks' pay ten years back.