The interviewer would like further detail on your education. Be sure to provide information that is not available on your resume. You could talk about your best classes, your favorite coursework, any student councils you were on, awards or accolades, and scholarships earned.
While attending post-secondary studies, you likely learned some core skills that would be transferable to your role as a Commercial Broker. Think about what you learned at your highest levels of education and how that knowledge applies to your work.
Whichever direction you choose to go with your response, be sure to tie your answer in with the ways that this educational experience will benefit you as a Commercial Broker.