Question 6: (10 points) Consider a network G with a start nodes and a destination nodet. We want to find a path to minimize the total cost from node s to nodet. We model this problem as a shortest path problem and plan to use Dijkstra algorithm to solve it. During solving, we just realize that the cost of one arc is negative. The cost of all other arcs is nonnegative. (a) (5 points): Will Dijkstra algorithm be able to find the optimal solution? If yes, why? If no, why not? (b) (5 points): Propose a better algorithm for this problem. You can either revise Dijkstra algorithm or propose a new algorithm. Why is it better