Who should provide consent for participants unable to give informed consent?

• A. The principal investigator alone.
• B. Legally acceptable representatives.
• C. The sponsor's medical director.
• D. The family can decide without process.

Answer: (B)

When someone cannot understand or appreciate the information about a study, someone with legal authority to make medical decisions on that person’s behalf must provide the consent. This ensures that decisions about participation reflect the person’s rights, values, and best interests and comply with applicable laws and ethics committee requirements. The person who signs consent isn’t the principal investigator or the sponsor’s medical lead, but a legally acceptable representative (or legally authorized representative) designated to make such decisions. Family members may be involved and can help convey the person’s preferences, but they cannot unilaterally decide without the formal authorization that the law and the ethics approval require. If the participant later regains capacity, they should be asked to re-consent to continue in the study.