This is a classic interview question, but never one I've found easy to answer, though this time it wasn't so bad. In this case, I said I hoped to be the editor of a section, branching out with my experiences. This was mainly because I know most magazine staff progress this way.
Absolutely terrible interview experience. Unprofessionally organised, terrible office space and the person who interviewed me was rude and had no interest in my application whatsoever. Would not have accepted the position if it had been offered.