The interviewer asks you about your five-year professional goals to gauge your ambition, motivation, and long-term career plans. Your answer can help them understand if your goals align with the organization's mission and vision, and if you have the potential to grow and contribute to their success in the long run. By asking this question, the interviewer also wants to know if you have a clear idea of what you want to achieve in your career and if you have a plan to work toward your goals. It's important to be honest and specific in your answer, as it can give the interviewer insights into your personality, work ethic, and overall fit for the role.