Which path to choose : DBA or PL/SQL development?

Making choice about which path you should take (DBA or PL/SQL programming), primarily depends upon your interest.
But for interest to be the deciding factor, you need to have knowledge of what activities are there in each path.
Best will be if you have some hands-on experience in both, then you will be in best position to decide which way to go.

If you ask me, I have experience in both, and have interest in both, so I am a mix of both that's why I ended up getting certified in both :)) ........

I will here mention some points about each path, as per my experience. Hope that will help in making a sound decision !

DBA path

PL/SQL path