Question 2 (a) A* search generates an optimal solution provided it is given an admissible heuristic. Describe what is an admissible heuristic, and how will it affect the optimality of A search. ( 3 marks) (b) The graph below represents a problem space. Nodes are labelled with a letter and a heuristic function h value. Edges are labelled with traversing cost. Suppose we want to use the Greedy Search algorithm on the graph to find the path from node S to node G. (i) Filling the table below. The table is a simulate running of Greedy Search algorithm on the graph, showing the h value of each node on the queue. If you find a new path to a node already on the queue, update its cost (using the lower h value) instead of adding another copy of that node to the queue. Keep the queue sorted. When two or more nodes are generated at the same time, the selection is based on the alphabetical order of their labels. (5 marks) (ii) For the solution found in (b)(i), give the cost and sequence of nodes comprising the path. (2 marks)