When you set a Cisco IOS Router as an SSH server, which command specifies the RSA public
key of the remote peer when you set the SSH server to perform RSA-based authentication?
A.
router(config-ssh-pubkey-user)#key
B.
router(conf-ssh-pubkey-user)#key-string
C.
router(config-ssh-pubkey)#key-string
D.
router(conf-ssh-pubkey-user)#key-string enable ssh
Correct !
Router(conf-ssh-pubkey-user)# key-string
Specifies the RSA public key of the remote peer and enters public-key data configuration mode.
Note You can obtain the public key value from an open SSH client; that is, from the .ssh/id_rsa.pub file.
http://www.cisco.com/c/en/us/td/docs/ios/sec_user_services/configuration/guide/15_0s/sec_securing_user_services_15_0S_book/sec_secure_shell_v2.html
Answer is correct:
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/sec_usr_ssh/configuration/15-e/sec-usr-ssh-15-e-book/sec-secure-shell-v2.html