Vivek said, "This boy is the husband of the only granddaughter of my father." How is Vivek related to the boy?

Father-in-law

The correct answer is Option (3) → Father-in-law

Step-by-Step Breakdown:

To solve blood relation puzzles, it is easiest to break the statement down from the end to the beginning:

1. "My father": This refers to Vivek's father.
2. "The only granddaughter of my father": For Vivek's father, his only granddaughter would be Vivek's daughter (assuming Vivek is the only son, or that the granddaughter mentioned is specifically through his lineage).
3. "Husband of the only granddaughter": This means the boy is the husband of Vivek's daughter.
4. "This boy is the husband...": So, the boy is Vivek's Son-in-law.

Relationship Check:

If the boy is Vivek's son-in-law, then Vivek is the Father-in-law of the boy.