单选题：For a given binary tree, if its post-order traversal sequence is

For a given binary tree, if its post-order traversal sequence is { 3, 4, 1, 6, 2, 5 }, pre-order traversal sequence is { 5, 3, 2, 1, 4, 6 }, then its in-order traversal sequence must be:



A.3, 5, 4, 1, 2, 6
B.3, 5, 1, 4, 2, 6
C.5, 3, 2, 1, 6, 4
D.cannot be determined


答案：D