d. The right to refuse to participate in the study is the ethical principle violated in the study.
Explanation:
Dr. Lewis decided to conduct a study on the television viewing habits of her students. So she demanded her students her complete and return the survey regarding their television viewing habits.
The survey is about making the self-report which is used to know about the feelings, attitudes and beliefs of the participant.
Lewis forced her students to complete the survey, here Lewis violates the rights of the students to refuse the survey.