Final answer:
B. at any time
Informed consent can be revoked at any time by a participant in a study. This right ensures that participation is voluntary and respects the autonomy and well-being of the study participants. It's a fundamental ethical principle in research involving human subjects.
Step-by-step explanation:
Once informed consent is given, it can be revoked at any time. Informed consent is a critical component of research ethics, ensuring that all study participants are fully informed about the study they are participating in, including the potential risks and benefits. They must be aware that their participation is voluntary and that they have the right to withdraw consent without any penalty.
Participants, or in cases involving minors, their parents or legal guardians, must provide informed consent before participating in a study. Furthermore, participants should be advised of their right to discontinue participation at any time, which is an essential aspect of respecting their autonomy and well-being. This discontinuation includes the revocation of informed consent.