B has a sister A. B is the daughter of C. C's father is P. How is A related to…

Concept: Full siblings share the same parents, so a parent stated for one sibling holds for the other too. Extending a further generation, if a person's parent has a father, that father is the person's grandfather -- making a female descendant his granddaughter.

Application:

1. A is the sister of B, so A and B share the same parents.

2. B is the daughter of C, so A is also the daughter of C.

3. C's father is P, making P one generation above C.

4. Since A is C's daughter and P is C's father, P is A's grandfather -- so A, being female, is P's granddaughter.

Cross-check:

• Aunt would need A to be C's sibling instead of B's -- not the given relationship.

• Niece would need A's parent to be P's sibling -- but A's parent, C, is P's own child.

• Sister (to P) would need A and P to be the same generation -- P is two generations above A.