Quiz: BFS vs DFS for Shortest Path

You need to find the shortest path in an unweighted grid from top-left to bottom-right. You implement DFS with backtracking to find all paths and return the shortest. What is the time complexity compared to BFS?

1. A.Same. Both are $O(V + E)$
2. B.DFS is faster because it does not use a queue
3. C.DFS with backtracking is exponential, while BFS is $O(V + E)$
4. D.DFS is slower by a constant factor only