What is necessary for Restricted Delivery?

Restricted Delivery is a specific mail service that requires the recipient, or addressee, to provide a signature upon receipt of the mail item. This feature ensures that only the intended recipient receives the package and adds an extra layer of security and accountability. By requiring the addressee's signature, the postal service can verify the identity of the person receiving the mail, thus safeguarding sensitive or important documents from falling into the wrong hands. This is essential for mailing items that may require special handling or that the sender wants to ensure are received by the right person.

The other options do not align with the principles of Restricted Delivery. For instance, leaving the item at the post office does not fulfill the requirement of direct delivery to the intended recipient, and not requiring a signature contradicts the fundamental aspect of Restricted Delivery. Additionally, delivering the item without notification compromises the security and tracking features designed for this type of service.