Tell me a time you demonstrated entrepreneurship?

The answer can be various, depend on what kind of career you are looking for.

If you go for marketing, your answer needs to be related to marketing.
If you go for management, also related to management.

for example, the interviewer pick a book from his table, and let you explain about the book.
If you go for design, you will tell them how to make this book look interesting and be user friendly.