Considering the desired result of the hypothesis test, we the closest mean time to 1.5 hours, hence the correct option is:
C. 1.6 hrs
The closer the mean is to the sample mean, the less likely we are to reject the null hypothesis.
In this problem, the sample mean is of 1.5 hours, hence, the closest value, considering the absolute value of the difference, is of 1.6 hours, hence option C is correct.
More can be learned about the test of an hypothesis at https://brainly.com/question/16313918