Can the IACUC suspend animal activities that it has never reviewed?

The rationale for why the correct choice is that the IACUC has the authority to suspend any animal activities if it determines that the activities are not compliant with ethical standards or regulations, which apply to all research involving animals. The IACUC's primary responsibility is to ensure the humane treatment of animals and adherence to federal guidelines and institutional policies.

In this context, the idea is that even if certain activities have not formally gone through the IACUC review process, if concerns arise regarding those activities—such as potential risks to animal welfare—the IACUC can intervene and suspend those activities. This authority is critical for maintaining the integrity of animal care and use within research institutions.

The other choices imply restrictions on the IACUC's ability to act, which is not aligned with its mandate to oversee all aspects of animal research, ensuring compliance and ethical standards from the outset, regardless of prior review.