Ramesh and Suresh are brothers. Dharmendra is the father of Ramesh, and Sunita is the wife of Suresh's only brother. Sapna is the daughter of Sunita. In this family relation puzzle, how is Sapna related to Dharmendra?

Introduction / Context:
This blood relation question combines information about two brothers, their father, and one brother's wife and child. The goal is to track how Sapna, the child mentioned, is connected to Dharmendra. Questions of this type test your ability to follow relational phrases like only brother and to automatically interpret standard family roles such as father, wife and daughter.

Given Data / Assumptions:
• Ramesh and Suresh are brothers.• Dharmendra is the father of Ramesh.• Suresh has only one brother.• Sunita is the wife of Suresh's only brother.• Sapna is the daughter of Sunita.• There is a normal nuclear family structure with no adoptions.

Concept / Approach:
The phrase Suresh's only brother is crucial. Since Ramesh and Suresh are brothers, and Suresh has only one brother, that brother must be Ramesh. Therefore, Sunita is the wife of Ramesh. We already know Dharmendra is the father of Ramesh. If Sunita is Ramesh's wife and Sapna is Sunita's daughter, then Sapna is the daughter of Ramesh and Sunita together. So from Dharmendra's perspective, Sapna is the child of his son. This is exactly the definition of a granddaughter.

Step-by-Step Solution:
Step 1: Interpret Suresh's only brother. Since Ramesh and Suresh are brothers and no other brothers are mentioned, Suresh's only brother is Ramesh.Step 2: Sunita is the wife of Suresh's only brother, so Sunita is the wife of Ramesh.Step 3: Sapna is the daughter of Sunita. In a normal family, Sunita and Ramesh are Sapna's parents.Step 4: Dharmendra is given as the father of Ramesh.Step 5: Because Ramesh is Dharmendra's son and Sapna is Ramesh's daughter, Sapna is a grandchild of Dharmendra.Step 6: Sapna is female, so she is specifically the granddaughter of Dharmendra.

Verification / Alternative check:
Visualise the family tree: Dharmendra at the top, with children Ramesh and Suresh. Ramesh is married to Sunita. Sapna is their daughter. From Dharmendra's point of view, Ramesh is his son and Sapna is the child of that son. This always gives the relation grandfather and granddaughter. No alternate reading of the phrase only brother changes this basic structure, so the conclusion is secure.

Why Other Options Are Wrong:
Daughter: Dharmendra's daughter would be his own child, but Ramesh is clearly his son and Sunita is Ramesh's wife, not Dharmendra's.Sister-in-law: A sister-in-law relationship would be between siblings or spouses, not between Dharmendra and Sapna.Niece: A niece would be the daughter of Dharmendra's sibling, not of his son.Cousin: Cousins share grandparents, not a direct parent child or grandparent grandchild relationship.

Common Pitfalls:
Some students incorrectly treat Suresh's only brother as a new character, forgetting that Ramesh is already introduced as his brother. Others quickly think that Sapna might be a niece of Dharmendra because siblings are mentioned. Systematically writing who is whose parent and spouse helps break this confusion and leads directly to the correct grandparent relationship.

Final Answer:
Sapna is the granddaughter of Dharmendra.