A common question at the Selection Board. It is mostly used in order to assess that you have an appropriate level of ambition for the role of a fast stream entrant. That you are ambitious needs to be at least evident to the interviewers!

They will probably expect you to show that you have been successful in many different contexts. This question can also reveal some more of your knowledge of the department you hope to enter.

You should certainly therefore be optimistic in your answer. Assume promotion will take place at regular intervals and anticipate where that would put you. Consider also where you might like to be and show that you have given the question some thought. This is no time to be modest!