The file /etc/ssh_known_hosts typically contains hosts keys for ______.
A.
all hosts that have logged into this server via ssh
B.
all hosts that users have logged into from this server via ssh
C.
clients allowed to connect to this host via ssh
D.
machines the system administrator trusts users to connect to using ssh
C and D are essentially the same answer.
Allowed to connect and trust are 2 diffrent things. If you connect to an Host wich isnt in this file your Client Show you the Fingerprint of the machine and asks for trust (Default behavior)