Blood Relations

Concept:Family tree relationships based on given statements.Explanation:• $Z$ is father of $Q$. • $Y$ is son of $Z$, so $Z$ is also father of $Y$. • $A$ is daughter of $Y$, so $Y$ is father of $A$. • $P$ is son of $Y$, so $Y$ is father of $P$. • $B$ is brother of $P$, so $B$ is also son of $Y$. • Thus $A$ (daughter) and $B$ (son) are children of $Y$, making $A$ the sister of $B$. • Other options are false: $B$ and $Y$ are father-son, not brothers; $Z$ is grandfather, not uncle of $B$; $Q$'s gender is unspecified, so cannot be assumed brother of $Y$.Answer:Option B: $A$ is sister of $B$.