Which one? Auditioning Roles ?

I would stay safe and go for Cathy if I were you. Just because you are going to have a ton of competition and its more important for them to cast someone who fits the part and can play it believably. Stretching yourself as an actor is great. However, its better to do in a non-audition situation such as an acting cl. Although if you are cast as a character opposite of you then that is an amazing opportunity for growth. Good luck!