P is the brother of Q and R. S is R's mother. T is P's father. Which of the following statements cannot be definitely true ?
Answer: E. Q is T's son.
P, Q, R are children of same parents. So, S who is R's mother and T, who is P's father will be mother and father of all three. However, it is not mentioned whether Q is male or female. So, (e) cannot be definitely true.