Pointing a photograph X said to his friend Y, "She is the only daughter of the father of my mother." How X is related to the person of photograph?

Nalni is the daughter of the only son of Gopi's grandfather. Hence, it's clear that Nalni is the sister of Gopi.

If D is Male, the answer is Nephew.

If D is Female, the answer is Niece.

As the sex of D is not known, hence, the relation between D and A cannot be determined.

Note: Niece - A daughter of one's brother or sister, or of one's brother-in-law or sister-in-law. Nephew - A son of one's brother or sister, or of one's brother-in-law or sister-in-law.

Ashok is the only brother of Sudeep and Veena is the sister-in-law of Ashok. Hence Veena is the wife of Sudeep. Kalyani is the mother-in-law of Veena. Kalyani is the mother of Ashok.

P x Q ? P is the wife of Q

Q % R ? Q is the father of R

R - T ? R is the brother of T

T + S ? T is the sister of S.

Therefore, T is the daughter of P.

Q - P ? Q is the mother of P

P + R ? R is the brother of P

Hence, ? q is the mother of R

R % T ? R is the father of T.

Hence, Q is the grandmother of T.

M x N ? M is the father of N

N - C ? N is the sister of C

and C + F ? C is the brother of F.

Hence, M is the father of C or C is the son of M.

Madhav is the only son of one of the sons of Varman's father ? Either Varman is the father or uncle of Madhav.

A $ B ? A is the brother of B

B * C ? B is the son of C

Hence, ? A is the son of C

C @ D ? C is the wife of D

Hence, ? C is the mother of A.

Since E is the brother of B

Therefore, A is the father of E

but D is the wife of E.

Hence, D is the daughter-in-law of A.