$1$ point

Imagine you$$re designing a robot that needs to navigate through a maze to reach a target. Which reward scheme would be most effective in teaching the robot to find the shortest path?

$+5$ for reaching the target, $-1$ for hitting a wall

$+5$ for reaching the target, $-0\mathrm{.}1$ for every second that passes before the robot reaches the target

$+5$ for reaching the target, $-0\mathrm{.}1$ for every second that passes before the robot reaches the target, $+1$ for hitting a wall

$-5$ for reaching the target, $+0\mathrm{.}1$ for every second that passes before the robot reaches the target