K is the brother of N and X. Y is the mother of N and Z is the father of K.
Which of the following statements is not definitely true ?

E. N IS THE BROTHER OF X.

All the six members of a family A, B, C, D, E and F are travelling together. B is the son of C but C is not the mother of B, A and C are a married couple. E is the brother of C. D is the daughter of A. F is the brother of B. How is E related to D ?

C. UNCLE

(I).   A, B, C, D, E and F are six members of a family.
(II).  One couple has parents and their children in the family.
(III). A is the son of C and E is the daughter of A.
(IV). D is the daughter of F who is the mother of E. How many female members are there in the family ?

C. FOUR

A woman walking with a boy meets another woman and on being asked about her relationship with the boy, she says, "My maternal uncle and his maternal uncle's maternal uncle are brothers."
How is the boy related to the woman ?

C. SON

Salesman, Engineer and Accountant. There are two married couples in the family. D, the Salesman is married to the Lady Teacher. The Doctor is married to the Lawyer. F, the Accountant is the son of B and brother of E. C, the Lawyer is the daughter-in-law of A. E is the unmarried Engineer. A is the grandmother of F. What is the profession of B ?

B. DOCTOR