$A$ is the father of $C$,and $D$ is the son of $B$. $E$ is the brother of $A$. If $C$ is the sister of $D$,how is $B$ related to $E$?

$A, B, C, D, E, F$ and $G$ are members of a family consisting of four adults and three children. Two of the children,$F$ and $G$,are girls. $A$ and $D$ are brothers and $A$ is a doctor. $E$ is an engineer married to one of the brothers and has two children. $B$ is married to $D$ and $G$ is their child. $A$ is the son of $C$. Who is $C$?

Looking at a portrait of a man,Harsh said,"His mother is the wife of my father's son. Brothers and sisters $I$ have none." At whose portrait was Harsh looking?

$A$ family consists of six members $P, Q, R, S, T$ and $U$. There are two married couples. $Q$ is a doctor and the father of $T$. $U$ is the grandfather of $R$ and is a contractor. $S$ is the grandmother of $T$ and is a housewife. There is one doctor,one contractor,one nurse,one housewife,and two students in the family. Who is the sister of $T$?

$P$ is the son of $Q$,while $Q$ and $R$ are sisters. $T$ is the mother of $R$. If $S$ is the son of $T$,which of the following statements is correct?

$A$ and $B$ both are children of $C$. If $C$ is the mother of $A$,$A$ is the son of $C$ but $B$ is not the daughter of $C$,how are $A$ and $B$ mutually related?