The correct answer is C) Misty and her faculty supervisor.
Misty, a graduate student, primarily designed and ran her own experiment. While her faculty supervisor and department chair did not make significant contributions to this study, her supervisor did answer a few statistics questions and the department chair provided her with laboratory space. Misty and her faculty supervisor should receive authorship credit.
It was Misty who in reality did all the research and the work. But as Misty received some kind of support when her supervisor did answer a few statistics questions, then she had to be thankful and share the credit with it. This shows class and education. It is not necessary to share the credit with the department chair because it provided her with laboratory space. This is part of the way the school supports students, to do their work. Maybe, a short mention or special thanks would be appropriate.