Consider the following graph with the start node S and goal node G. D 5 1 1 3 3 2 S A E G 1 2 1 B Consider three heuristic functions, h1, h2, and h3. Below are shown the estimated costs to the goal, G, for each of the three heuristics: Node h1 h2 h3 S A B D E G 6 5 5 4 2 2 0 6 5 4 2 1 1 0 6 6 5 3 2 1 0 a) Which of the three heuristics are admissible heuristics? Explain why. b) For each of the admissible heuristics, list the notes in the order in which they are visited by the A* search. c) Only for heuristic h2 list the notes in the order in which they are visited by the best-first greedy search