With which publishing categories are you most familiar? How will this knowledge help you in this position with HarperCollins?

There is a multitude of publishing categories in which you could bring experience. This experience includes magazines, physical books, ebooks, catalogs, online publishers, newspapers, and more. Discuss with the interviewer the areas which you are most experienced. If you want to dive deeper into genres, you can certainly do that as well; especially if your experience is related to the publishing activities at HarperCollins. Be sure to sound confident, and finish your answer by tying in how this experience will make you successful in your new role.