P is brother of Q and R; S is R's mother; T is P's father.
Which statement cannot be true?
I. T is Q's father
II. S is P's mother
III. P is S's son
IV. Q is T's son

Question: 以下哪项是正确的？
Options:
A. 仅 I, B. 只有 IV, C. 非 III, D. 仅 III, E. II 或 I
Answer: B
C
True statement: IV