If the research focus or question relates to the number of hours students spend in an online course and the final course grade, which of the following is a workable null hypothesis?
a. Students who spend 10 hours or more logged into an online course do not receive a grade above a B.
b. Students who spend 10 hours or more logged into an online course receive a grade of A or B.
c. Students need to have great time management skills to get an A in an online course.
d. The course learning management system should determine how many hours per week are required for a student to get a passing course grade.