Pointing to a man in a photograph, a woman said, "His brother`s father is the only son of my grandfather.' How is the woman related to the man in the photograph?

A. Mother
B. Aunt
C. Sister
D. Daughter
E. Grandmother
Answer: C . Sister

Justification: Only son of woman's grandfather -- Woman's father;
Man's brother's father -- Man's father.
So, the woman is man's sister.