A Linux systems administrator is setting up SSH access with PKI for several using their newly created RSA keys. Which of the following MOST securely achieves this task?
A. Use curl to copy each user’s public key file to the respective system
B. Use cp to copy each user’s public key file to the respective system
C. Use ssh-copy-id to copy each user’s public key file to the respective system
D. Use ssh-copy-id to copy each user’s private key file to the respective system