Which of the Following Are Examples of Types of Research

Which of the following are examples of types of research questions that can be answered with a test of inference about independent variances?

A) Is there a relationship between book price and tuition?
B) Are there similar proportions of U.S. versus non-U.S. board graduates?
C) Is the variation in graduation rate for public colleges different than the graduation rate for private colleges?
D) Does weight vary for athletes who train 6 hours per day as compared to athlete who train 8 hours per day?
E) Is there a relationship between satisfaction with a job's salary and satisfaction with a job's level of responsibility?
F) Is there a mean difference in engagement in the workplace based on whether an employee is full-time or part-time?