
FreeBSD using C shell for the root user, and the user got sh for their shell by default. And there are so many shell can be used. But why you want to use bash at the first place, in FreeBSD terminal ?
One thing for sure, every Linux distribution by default using Bash as their shell of choice. This will get some compatibility if you create script which not run in Bash. So the options was you use bash or you change your script.
So the option to...