A safety officer wants to prove that= the average speed of cars driven by a school is less than 25 mph. Suppose that a random sample of 14 cars shows an average speed of 24.0 mph, with a sample standard deviation of 2.2 mph. Assume that the speeds of cars are normally distributed.For a significance level of= 0.05, do we reject the null hypothesis? Which of the following is an appropriate conclusion?

A: The results are statistically significant so the average speed appears to be greater than 25 mph.

B: The results are statistically significant so the average speed appears to be less than 25 mph.

C: The results are not statistically significant: there is not enough evidence to conclude the average speed is less than 25 mph.