An administrator finds in a local study that 45% of his university's students obtain an undergraduate degree in 4 years of study (based on 400 randomly selected students). Assuming that the national average for students graduating in 4 years is 39% and that the probability of observing this sample mean of 45% or higher was 0.1, what conclusioncan the administrator make about his university's graduation rate?
A. There is enough evidence to conclude that it is higher than the national average.
B. There is not enough evidence to conclude that it is higher than the national average.
C. The sample size is not large enough to draw any statistical conclusions.
D. There is enough evidence to conclude that it is lower than the national average.