下面哪一个可能是某图的深度优先遍历序列? A. 1, 5, 4, 8, 7, 9, 6, 3, 2B. 1, 5, 8, 4, 7, 9, 6, 3, 2C. 2, 5, 8, 7, 9, 6, 3, 4, 1D. 8, 9, 6, 3, 2, 5, 1, 4, 7 正确答案:B