To communicate that a document is using a digital signature, which one of the following is the next step in the process after a hash of the document is calculated by the sender?

Appending an unencrypted hash provides no cryptographic protection - an attacker could modify the document and recalculate a matching hash without detection.

Storing the hash locally does nothing to convey a verifiable signature to the receiving party and provides no authentication or integrity guarantee for the receiver.

The sender encrypts the computed hash using their own private key, which is the operation that produces the digital signature. Because only the sender possesses the corresponding private key, this step ensures non-repudiation and authenticity. Any recipient can then decrypt the signature using the sender's public key and compare the resulting hash to a freshly computed one, verifying integrity.

Symmetric encryption of the hash does not produce a valid digital signature because any party sharing the symmetric key could have created it, eliminating the non-repudiation property.

The receiver's public key is used to encrypt data for confidentiality, not for creating a digital signature - signing requires the sender's private key, not the receiver's public key.