A. B, C, D, and E traveled by high-speed rail, and they happened to be sitting in the same row of A. B. C. D. F five seats. Known? (1) If one of A or B is sitting in Block C, then C is sitting in Block B; (2) If E is sitting in Block C, Ding is sitting in Block F. If Ding is sitting in Block B, then it is certain that? ['A sits in Block A.', 'Sitting in Block D.', 'C sitting in Block C.', 'E sitting in Block F.']