A is B's Sister. C is B's mother .D is C's father. E is D's mother. How is A…

Concept: In blood-relation puzzles, convert every stated relation into a parent-child (or sibling) link, then trace the two people asked about through their shared connections in the family tree.

Application

1. A is B's Sister, so A and B are siblings who share the same parents.

2. C is B's mother, so C is the mother of both A and B (since A and B are siblings).

3. D is C's father, so D is one generation above C — that places D two generations above A and B.

4. E is D's mother, so E sits one generation above D; this link is not needed to connect A and D.

D is the father of A's mother, C — that makes D the maternal grandfather of A. Since the first statement identifies A as female ('A is B's Sister'), A is D's granddaughter.

Cross-check: Viewed from D's side — D's daughter is C, and C's children are A and B — so A and B are D's grandchildren, confirming A is D's granddaughter.