Answer: The answer is b). Confidential
Explanation: In the data collection process, when researchers are trying to obtain information from survey participants, it is ethical to indicate that the survey will be conducted anonymously or confidentially. Confidentiality refers to a condition in which the researcher knows the identity of a research subject, but takes steps to protect that identity from being discovered by others. One way of identifying the subjects is to assign an identifying number or code to each participant.