单选题：$\alpha$-$\beta$ Pruning

For the game tree shown below, for which values of $x$ the dashed branch with the scissors will be pruned by $\alpha$-$\beta$ pruning? (Assume that the nodes are evaluated left to right)






A.x≤2
B.x≥3
C.x≤6
D.Pruning will happen for all values of x


答案：B