单选题：Which one of the following is NOT a topological order of the giv

Which one of the following is NOT a topological order of the given directed graph shown by the figure? @[D](3)



A. 1, 5, 2, 3, 6, 4
B. 5, 1, 2, 6, 3, 4
C. 5, 1, 2, 3, 6, 4
D. 5, 2, 1, 6, 3, 4




A.1, 5, 2, 3, 6, 4
B.5, 1, 2, 6, 3, 4
C.5, 1, 2, 3, 6, 4
D.5, 2, 1, 6, 3, 4


答案：D