Quiz: Dijkstra on Grids

In the Minimum Effort problem, the "edge weight" between $2$ adjacent cells is the absolute difference in heights. You want to minimize the maximum edge weight along a path. What is the time complexity of Dijkstra on an $n \times m$ grid?

1. A.$O(nm)$
2. B.$O(n^2 m^2)$
3. C.$O(nm \log(nm))$
4. D.$O(nm \cdot (n + m))$