Which of the following is the BEST method to securely transfer a message?

A.
Password-protected removable media

B.
Facsimile transmission in a secured room

C.
Using public key infrastructure (PKI) encryption

D.
Steganography

Explanation:
Using public key infrastructure (PKI) is currently accepted as the most secure method to transmit e-mail messages. PKI assures confidentiality, integrity and nonrepudiation . The other choices are not methods that are as secure as PKI. Steganography involves hiding a message in an image.