In which scenario is a signature witness required?

The requirement for a signature witness occurs when the notary public does not have satisfactory evidence as outlined in the applicable laws. In this context, option B is correct because when the signer is personally known to the notary or satisfactory evidence is provided, there is typically no need for an additional witness. However, if neither of these conditions is met, having a witness present can serve as an additional safeguard to verify the authenticity of the signature and the identity of the signer.

The other scenarios do not inherently require a witness. For example, when an oath is involved as part of the verification process, it doesn't automatically necessitate a witness. Additionally, while witnessing in a public place can sometimes be a best practice, it does not establish a legal requirement for a signature witness. Finally, asserting that all signings must have a witness present is incorrect because many notarial acts can be completed without one if the proper identification and evidence requirements are satisfied.