Pointing to a boy in a photograph, Anil said, “His father's sister is the only daughter of my father's father.” How is the boy's father related to Anil?​​

Given: 

Pointing to a boy in a photograph, Anil said, “His father's sister is the only daughter of my father's father.”

The boy's father is father's brother of Anil.

Thus, correct option is (a).