If you wanted to restrict the SSH access to only the user freddy, what option in which file should you modify?

a$.$ The option Permitusers in $/$etc$/$ssh$/$ssh$\_$config

b$.$ The option AllowUsers in $\frac{}{.}5s\frac{h}{s}sh{d}_c$onfig

c$.$ The option AllowUsers in $/$etc$/$ssh$/$sshd$\_$config

d$.$ The option Permitusers in $/$etc$/$ssh$/$sshd$\_$config