Final answer:
Option (a), Under no circumstances can a co-worker of a notary use their notarial stamp, as it is only permissible for the commissioned notary to use it to maintain the integrity of notarized documents.
Step-by-step explanation:
A co-worker of a notary can use the notarial stamp Under no circumstances. Notarial acts are highly regulated by law, and the use of a notary's official stamp is restricted to the notary public who is commissioned to handle notarizations.
The integrity of notarized documents depends crucially on the assurance that the person affixing the stamp is a notary public in good standing, who has verified the identity of the signers and their understanding and willingness to sign. As such, it is not permissible for anyone other than the commissioned notary to use their stamp, even with written permission or employer directive.