How to Answer

By asking this question, the interviewer is trying to establish how committed you are to staying with the company. Given that they're prepared to put in the effort and expense into training you, they won't look very favorably on someone who is using them until something better comes along. Perhaps, you can say that you're interested in starting out in this position and within 5 years, you're hoping to specialize in a certain area and are willing to undergo training and certifications to further enhance your career. This kind of answer shows commitment and will impress the interviewer.