ANSWER : Niece

Explanation : . Son of woman's mother's mother means the brother of mother. And brother of mother is maternal-uncle. Hence, woman is related as niece to that man.

ANSWER : Father

Explanation : . The daughter of A's grandmother is the sister of A's father and the only brother of A's father is A's father himself. Hence, A met his father.

ANSWER : Data inadequate

Explanation : . From the information given in the question, it is clear that S is the mother of R (who's sex is not known). N is the daughter of R and sister of M (whose sex is not known). Therefore, on the basis of information, we conclude that M may be male or female, hence may be son or daughter of R or son or daughter of S. Hence, data is inadequate.

ANSWER : Data inadequate

Explanation : . From the information given in the question, the sex of M is not determined, hence, none of the options is a definite answer.

ANSWER : Sister

Explanation : . Only son-in-law of mother of Poonam's mother is the father of Poonam and his son is the brother of Poonam. Therefore, Poonam attended the birthday party of her brother.