In such a type of question Interviewer wants to know your commitment with the organisation whether it is for long term or short term. As an answer you should assure the interviewer that you are going for long term commitment.
For Example- This position entails exactly what I am looking up to and what I do extremely well. Since I am a fresher, after 5 years I must have satisfactory salary, a good position in the corporate world and of course I can see myself few steps ahead of my dream job that is CEO of a MNC.