Quiz: Finding the Centroid

To find the centroid of a tree, you compute subtree sizes and walk toward the heaviest subtree. When do you stop?

1. A.When you reach a leaf node
2. B.When the current node has the smallest subtree size
3. C.When you have visited all nodes
4. D.When no adjacent subtree has more than $\lfloor n/2 \rfloor$ nodes