solve a Knapsack Problem using a depth$-$first search with pruning $($aka backtracking$)$

For this problem, assume you have a knapsack with a capacity of $6$ lb$.$ and the following $4$ items:

Item $1$: $$10/1$ lb$.$

Item $2$: $$18/2$ lb$.$

Item $3$: $$32/4$ lb$.$

Item $4$: $$14/2$ lb$.$

Your task is to draw the pruned state space tree $.$ Be sure to mark the non$-$promising nodes with an X to show that they are non$-$promising. Also clearly mark the node that corresponds to the optimal solution.