The correct answer is: C. Path cost from start node to current node + Heuristic cost.
The A* search algorithm is an algorithm for finding the shortest path between two nodes in a graph. It is a heuristic search algorithm, which means that it uses a heuristic function to estimate the cost of the remaining path from a node to the goal node. The heuristic function is not guaranteed to be accurate, but it can help to find the shortest path more quickly than a blind search.
The evaluation function in A* is the sum of the path cost from the start node to the current node and the heuristic cost from the current node to the goal node. The path cost is the actual cost of the path from the start node to the current node, and the heuristic cost is an estimate of the cost of the remaining path from the current node to the goal node.
The evaluation function is used to compare the cost of different paths. The path with the lowest evaluation function is the path that A* will follow.
A* is a very efficient algorithm, and it is often used to find the shortest path in large graphs. It is also used in other applications, such as planning and scheduling.
Here is a brief explanation of each option:
- A. Heuristic function. The heuristic function is an estimate of the cost of the remaining path from the current node to the goal node. It is not guaranteed to be accurate, but it can help to find the shortest path more quickly than a blind search.
- B. Path cost from start node to current node. The path cost is the actual cost of the path from the start node to the current node. It is calculated by adding up the costs of the edges on the path.
- C. Path cost from start node to current node + Heuristic cost. The evaluation function in A* is the sum of the path cost from the start node to the current node and the heuristic cost from the current node to the goal node.
- D. Average of Path cost from start node to current node and Heuristic cost. This is not the evaluation function used in A*.