If $(i)$ $M$ is brother of $N$; $(ii)$ $B$ is brother of $N$; and $(iii)$ $M$ is brother of $D$,then which of the following statements is definitely true?

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?

$Q's$ mother is the sister of $P$ and the daughter of $M$. $S$ is the daughter of $P$ and the sister of $T$. How is $M$ related to $T$?

Read the following information carefully and answer the question given below. All the six members of a family $A, B, C, D, E,$ and $F$ are travelling together. $B$ is the son of $C$ but $C$ is not the mother of $B$. $A$ and $C$ are a married couple. $E$ is the brother of $C$. $D$ is the daughter of $A$. $F$ is the brother of $B$. How is $E$ related to $D$?

Five persons namely $P, Q, X, Y,$ and $Z$ are sitting in a park. $P$ is the mother of $X$,who is the wife of $Z$. $Y$ is the brother of $P$,and $Q$ is the husband of $P$. How is $Q$ related to $Z$?

Five persons namely $P, Q, X, Y,$ and $Z$ are sitting in a park. $P$ is the mother of $X$,who is the wife of $Z$. $Y$ is the brother of $P$,and $Q$ is the husband of $P$. How is $X$ related to $Q$?