In human subjects research, informed consent should be?

• A. Voluntary, in Writing, and Witnessed
• B. Informed Consent Is Optional
• C. Voluntary, Informed, and Documented
• D. Verbal Consent Alone Suffices

Answer: (C)

In human subjects research, informed consent should be voluntary, informed, and documented. Voluntary means participants decide freely, without coercion, threats, or undue influence, and they know they can withdraw at any time without penalty. Informed means researchers disclose enough information about the study—the purpose, procedures, risks, benefits, alternatives, and privacy protections—and ensure the participant understands it before agreeing. Documented means there is a record of the person's consent, typically a signed consent form or approved electronic record, unless a formal waiver is granted. The other options either treat consent as optional, allow only verbal consent, or impose unnecessary specificity like requiring witnessed consent in all cases; the three elements together reflect the standard ethical requirement.