Quiz: DFS State Tracking

You run DFS on a tree where each node stores a value. You want to count how many root-to-leaf paths have a sum greater than $100$. Where in the DFS code should you check if the path sum exceeds $100$?

1. A.Only at leaf nodes (nodes with no unvisited children)
2. B.At every node during the traversal
3. C.Only at the root before starting DFS
4. D.After DFS finishes, using the returned values