To ensure authentication, confidentiality and integrity of a message, the sender should encrypt the hash of the message with the senders:

A. public key and then encrypt the message with the receivers private key.

B. private key and then encrypt the message with the receivers public key.

C. public key and then encrypt the message with the receivers public key.

D. private key and then encrypt the message with the receivers private key.

Explanation:

Obtaining the hash of the message ensures integrity; signing the hash of the message with the senders private key ensures the authenticity of the origin, and encrypting the resulting message with the receivers public key ensures confidentiality. The other choices are incorrect.