The interviewer wants to know that you aren't just going to stick around for a little bit and want to make sure you have plans to stay. This isn't a trap question, no one is expecting you to say that you plan on working for their center till the end of your career. If you have hopes to grow further with the company, feel free to share that because that will show commitment. Don't lie to the interviewer if that is not what you want though.

If you don't know where you see yourself in ten years, you can talk about different opportunities for growth that you are looking into. For example, different trainings that are available for yourself- there are many different training opportunities that you can find online in your state; research a few prior to your interview.