The A* algorithm is optimal when,

1. AIt always finds the solution with the lowest total cost if the heuristic 'h' is admissible.
2. BAlways finds the solution with the highest total cost if the heuristic 'h' is admissible.
3. CFinds the solution with the lowest total cost if the heuristic 'h' is not admissible.
4. DIt always finds the solution with the highest total cost if the heuristic 'h' is not admissible.

Pick an option to check yourself, or open the answer below.

Show answer & explanation

Correct answer: A. It always finds the solution with the lowest total cost if the heuristic 'h' is admissible.

Explanation

With an admissible heuristic (one that never overestimates), A* tree search finds a lowest-cost solution.