Often times, the part of your job that you love most is what you are also best at. The hiring manager is looking for further insight into what you like most and are best at. Tell the interviewer what you love most about your career.
"For me, the most rewarding part of being a QC Inspector is that I am able to help a company create an unbeatable product. It's always an exciting challenge to be the best in your industry and that really is what drives me."