Final answer:
An experimenter must ensure privacy, anonymity, and confidentiality for research participants, but sincerity, while important, is not a specific responsibility like the others listed.
Step-by-step explanation:
An experimenter's responsibilities during a research study include ensuring the privacy, anonymity, and confidentiality of the participants. These are essential ethical considerations that must be established to protect the participants and maintain the integrity of the research. The option that is NOT an experimenter's responsibility is c) Sincerity. While researchers should conduct their studies sincerely, sincerity is more of an expectation for personal behavior and general ethical conduct rather than a specific responsibility to research participants, as are the other options listed.