Which of the following is a key document required by Good Clinical Practice (GCP)?

The clinical trial protocol is a key document required by Good Clinical Practice (GCP) as it outlines the objectives, design, methodology, statistical considerations, and organization of a clinical trial. This document serves as a blueprint for conducting the study and ensures that all aspects of the trial are systematically documented and adhered to throughout the study's duration. It plays a critical role in protecting the integrity of the trial and ensuring the safety of participants while providing valid results that can be used for regulatory submission and approval.

While case report forms, investigator brochures, and patient medical history are also important documents within a clinical trial, the protocol is central to the organization and conduct of the trial. It establishes the framework for everything else, ensuring that all stakeholders, including sponsors, investigators, and regulatory bodies, have a clear understanding of the study's design and requirements. Therefore, the clinical trial protocol is indispensable in the context of GCP.