Your interviewer is interested in how you invest the time necessary to stay up-to-date on the latest buzz topics, developments, and trends in your industry. As the oldest and largest of the "Big Three" management consultancies, McKinsey and Company expect those who represent their brand to be industry leaders and reliable resources of information. Share the resources you rely on to keep your knowledge as current and up-to-date as possible. Demonstrate that you bring your best to work every day and that your coworkers and clients can count on you as their go-to resource. Turn the question on your interviewer. Asking about their trusted reference materials is a great way to express a continual desire to learn and compete and a memorable method of getting to know them and their personal preferences. It will also exhibit your interpersonal skills.