Quiz: Offline Processing

You have queries asking "are $u$ and $v$ connected using only edges with weight $\leq w$?" You sort edges by weight and queries by their weight limit. Why does this approach work?

1. A.Because DSU operations are commutative, so order does not matter
2. B.Because DSU automatically tracks edge weights
3. C.Because sorting lets you add edges incrementally and answer each query at the right moment
4. D.Because queries with smaller weight limits always return false