$P + Q$ means $P$ is the brother of $Q$; $P - Q$ means $P$ is the mother of $Q$; and $P \times Q$ means $P$ is the sister of $Q$. Which of the following means $M$ is the maternal uncle of $R$?

Showing a lady in the park,Ashok said,'She is the daughter of my grandfather's only son'. How is Ashok related to that lady?

$C$ is $A's$ father's nephew. $D$ is $A's$ cousin but not the brother of $C$. How is $D$ related to $C$?

Pointing to a lady,a girl said,"She is the daughter-in-law of the grandmother of my father's only son." How is the lady related to the girl?

$A$ 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 $T$?

$A$ 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?