Welcome to your interview.
The question is on your right: Diagnosing Drop in Usage. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
If you notice active usage dropping significantly in an enterprise account three months after onboarding, what is your immediate diagnostic action plan?