This is a data sufficiency question -
Q - How is A related to B?
Statement I. B is the only son of D who is the daughter of A's father.
Statement II. B is the father of C and is the only son of A's mother.
A -
I. If statement I alone is sufficient to answer the question.
II If statement II alone is sufficient to answer the question.
III If the data either in statement I or statement II alone is sufficient to answer the question.
IV If both the statement together is not sufficient to answer the question.
V If both the statement together is necessary to answer the question.
MY ATTEMPT
I think the answer will be Option I.
From statement I, I got A is the uncle of B
From statement II, I got A is the sister or the brother of B
But I am not sure if I am right.
Please help me solve this question.
Statement I: D has a unique male child. D's male child is named B. D is a daughter, so D is female. D is the child of an unnamed male called A's father. A is a child of an unnamed male called A's father.
(using ":" for children and "()" for collecting sibling subtrees...)
A's father - male: (A - unknown sex, D - female : B - male)
Statement II: B is a father, so is male. B has a child named C. B is a child of an unnamed female called A's mother. A is a child of an unnamed female called A's mother.
A's mother - female: (A - unknown sex, B - male: C - unknown sex)
A is an aunt or an uncle of B, but neither statement is sufficient to resolve which is the case. A is also a sibling of B, but neither statement is sufficient to resolve the sex of A and therefore whether A is a brother or a sister to B.
Interestingly, B's mother is D (statement I), D's father is A's father (statement I) and B's father is A's father (statement II). Therefore B's mother is also his half-sister.