An engineer has designed an improved light bulb. The previous design had an average lifetime of 1200 hours. Based on a sample of 2000 of these new bulbs,the average lifetime was found to be 1201 hours. Although the difference is extremely small,when the calculations were completed,the effect was found to be statistically significant. What is the best explanation? A) The sample size is very large, so that even a small difference can be detected. B) New designs typically have more variability than standard designs. C) The mean of 1200 is large. D) The relative improvement in average lifetime is 0.000083, which is much smaller than 0.05.