Consider the search problem represented by the grid below. The agent is marked with the letter $"$A$"$ and the goal location with the letter $"$G$".$ In this problem, the agent can move up$,$ down, left, or right. All actions cost $1\mathrm{.}0$

$.$

Given this context, which grid better represents the Dijkstra's search once it returns the answer? Each gray cell represents a state in the CLOSED list.

Hints:

The goal state is never expanded because the search stops once it comes out of OPEN.

When a state is generated, it is added simultaneously in both OPEN and CLOSED lists.

Once a state is expanded, all its children are considered for addition to OPEN and CLOSED.

Question $1$Answer

a$.$

b$.$

c$.$

d$.$