Quiz: Combining with Data Structures

You flatten a tree using an Euler tour and build a segment tree over the resulting array. What operations can you now perform in $O(\log n)$ time?

1. A.Only subtree sum queries
2. B.Only point updates on individual nodes
3. C.Finding the LCA of two nodes
4. D.Subtree queries, subtree updates, and (with the entry-exit variant) path queries