Quiz: Directed Transition

In the Choosing Capital problem, you root the tree at node $1$ and run a DP. What does dp[u] count?

1. A.The number of edges in u's subtree pointing toward u
2. B.The number of edges in u's subtree that need reversal so u can reach all nodes in its subtree
3. C.The depth of node u in the rooted tree
4. D.The number of children of u