Final answer:
A Notary Public must either witness the person signing a document or have the person acknowledge their signature in person.
Step-by-step explanation:
A Notary Public is responsible for certifying the signature on a legal document as required by law. In order to do this, the Notary Public must either see the person sign the document or have the person acknowledge to the Notary Public in the Notary Public's presence that they are the signer. The Notary Public cannot recognize a person's signature if they did not see the person sign, nor can they hear the person acknowledge the signature over the phone.
Learn more about Notary Public and certification of signatures on legal documents