Your question is Defending Against Zero-Days. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Explain what a zero-day exploit is. How would a security team defend against something they don't yet know about?
Answer as a Security Engineer. Define the concept clearly, then explain how you would reduce the likelihood and impact of an unknown vulnerability through prevention, detection, containment, response, and recovery. Discuss how you would prioritize actions during an active incident.