State the conclusion based on the results of the test. The standard deviation in the pressure required to open a certain valve is known to be sigma equals 1.1 psi. Due to changes in the manufacturing process, the quality-control manager feels that the pressure variability has changed. The null hypothesis was not rejected. Choose the correct answer below. A. There is not sufficient evidence that the standard deviation in the pressure required to open a certain valve has not changed. B. There is sufficient evidence that the standard deviation in the pressure required to open a certain valve has not changed. C. There is sufficient evidence that the standard deviation in the pressure required to open a certain valve has changed. D. The standard deviation in the pressure has changed. E. The standard deviation in the pressure has not changed. F. There is not sufficient evidence that the standard deviation in the pressure required to open a certain valve has changed.