$A$ is the son of $B$. $C$,$B$'s sister,has a son $D$ and a daughter $E$. $F$ is the maternal uncle of $D$. How many nephews does $F$ have?

Pointing to a girl in the photograph,Amar said,"Her mother's brother is the only son of my mother's father." How is the girl's mother related to Amar?

Pointing to a man in a photograph,Asha said,"His mother's only daughter is my mother." How is Asha related to that man?

Pointing to a photograph,Nikita said,'She is the only granddaughter of my grandmother's daughter'. How is the girl in the photograph related to Nikita?

There is a family of six persons $A, B, C, D, E,$ and $F$. They are lawyer,doctor,teacher,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 $F$. Which of the following is one of the couples?

Introducing a man to her husband,a woman said,"his brother's father is the only son of my grandfather." How is the woman related to this man?