It is night and you control a single insect. You know the maze, but you do not know what square the insect will start in$.$ You must pose a search problem whose solution is an all$-$purpose sequence of actions such that, after executing those actions, the insect is guaranteed to be on the exit square, regardless of initial position. The insect executes the actions mindlessly and does not know whether its moves succeed: if it uses an action which would move it in a blocked direction, it will stay where it is$.$ For example, in the maze below, moving right twice guarantees that the insect will be at the exit regardless of its starting position.

Which of the following are admissible heuristics?

A$.$ Total number of possible locations the insect might be in$.$

B$.$ The maximum of Manhattan distances to the exit square from each possible location the insect could be in$.$

C$.$ The minimum of Manhattan distances to the exit square from each possible location the insect could be in$.$