Final answer:
Protocol adherence is an investigator's commitment to the sponsor in medical or clinical research, ensuring the study follows the approved plan.
Step-by-step explanation:
Among the listed options, an investigator’s commitment to the sponsor is c) Protocol adherence. In the context of medical or clinical research, investigators are expected to strictly follow the protocol agreed upon with the sponsor of the research. This adherence ensures that the study is conducted as was originally approved, typically by an Institutional Review Board (IRB), and is essential for the validity and integrity of the research. While informed consent is also crucial, it primarily relates to the ethical obligation researchers have towards study participants to inform them about the study and obtain their voluntary consent. Adverse event reporting and financial disclosure are also important but are not typically commitments made to the sponsor, rather they are regulatory and ethical obligations.