Yes, its possible to add host entry to known_hosts automatically without give a yes word.
Option "-o" is used to give options in the format used in the configuration file and there is no separate command-line flag.
It's very helpful to connect the server remotely in scripts.
Another one is executing default command automatically once logged into server, for the testing I have used top -c command to run on,
option -t is force pseudo-tty allocation. this is used execute arbitrary screen-based programs on a remote machine.