Q$4.(10$ points$)$

a$)$ Consider the zero$-$sum game tree shown below. Triangles that point up$,$ such as at the top node $($root$),$ represent choices for the maximizing player; triangles that point down represent choices for the minimizing player. Assuming both players act optimally, fill in the minimax value of each node. $(5$ points$)$

b$)$ Which nodes can be pruned from the game tree above through alpha$-$beta pruning? If no nodes can be pruned, explain why not. Assume the search goes from left to right; when choosing which child to visit first, choose the left$-$most unvisited child. $(5$ points$)$

Answer: