Pointing to a girl Sandeep said, “She is the daughter of the only sister of my father.” How is sandeep related to the girl?

The correct answer is: Uncle.

Sandeep’s father has a sister. This sister has a daughter. This daughter is Sandeep’s niece. Sandeep is therefore the girl’s uncle.

A cousin is the child of one’s aunt or uncle. A father is the male parent of a child. A grandfather is the father of one’s father or mother.

In this case, Sandeep is not the girl’s cousin, father, or grandfather. He is her uncle.