Welcome to your interview.
The question is on your right: K-Means WCSS and Cluster Choice. 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.
Explain the concept of Within-Cluster Sum of Squares (WCSS) and how it is used to determine the optimal number of clusters in K-Means.