A school counselor suspects that, on average, students at their school are sleeping less than 8 hours per night. They survey a random sample of students about how many hours they slept the previous night to see if their average sleep amount is significantly less than 8 hours.
What type of statical test used in this case?

A. A χ2 goodness of fit test
B. A χ2 test for homogeneity
C. A two-sample z-test for a proportion
D. A χ2 test of independence
E. A t-test for mean