The preorder traversal sequence of a binary search tree is 30, 20, 10, 15, 25, 23, 39, 35, 42.Which one of the following is the postorder traversal sequence of the same tree?( )
选项：

A:10, 20, 15, 23, 25, 35, 42, 39, 30
B:15, 10, 25, 23, 20, 42, 35, 39, 30
C:15, 20, 10, 23, 25, 42, 35, 39, 30
D:15, 10, 23, 25, 20, 35, 42, 39, 30