Employers expect their staff to stay up-to-date in their respective fields, and today's technology makes this reasonably easy! List several ways you receive your industry knowledge and stay on top of trends.
Tell the interviewer about those daily email updates you receive from professional organizations, conferences you attend, and seminars you have taken.
Lastly, asking the interviewer what resources they refer to for industry trends is a great idea. That question can start up a great conversation, and you may learn a thing or two as well.