What is the investigator's responsibility regarding trial conduct?

• A. The investigator may delegate all responsibilities to staff.
• B. The investigator is only responsible for data entry.
• C. The investigator is responsible for the proper conduct of the trial and must ensure compliance with the protocol.
• D. The investigator's role ends after enrollment.

Answer: (C)

The central idea is that the investigator has ultimate responsibility for the proper conduct of the trial and must ensure it is carried out in accordance with the protocol. Tasks may be delegated to qualified staff, but the investigator remains accountable for all aspects at the site, including protecting participants, obtaining and maintaining informed consent, ensuring data integrity, and monitoring safety and protocol compliance. This describes the investigator’s duty to supervise the trial and address deviations promptly. Delegating all responsibilities would remove necessary oversight, data entry alone does not capture the full scope of accountability, and the investigator’s role continues beyond enrollment to ongoing conduct and reporting.