(i) A, B, C, D, E and F are six members in a family in which there are two married couples. (ii) D is brother of F. Both D and F are lighter than B. (iii) B is mother of D and lighter than E. (iv) C, a lady, is neither heaviest nor the lightest in the family. (v) E is lighter than C. (vi) The grandfather in the family is the heaviest.
Which of the following is a pair of married couples ?
A is the brother of B. B is the brother of C. D is the father of A. Based on these three satatements, which of the following statements cannot be definitely true ?