The correct answer is D. His nephew’s.
The man in the photograph is the man’s nephew. The man says that he has no brother or sister, but that the man in the photograph’s father is his father’s son. This means that the man in the photograph is the son of the man’s brother or sister. The man’s brother or sister is the man’s uncle or aunt. The man’s nephew is the son of the man’s uncle or aunt. Therefore, the photograph is of the man’s nephew.
A. His own: This is incorrect because the man says that he has no brother or sister.
B. His son’s: This is incorrect because the man says that the man in the photograph’s father is his father’s son. This means that the man in the photograph is the man’s nephew, not the man’s son.
C. His father’s: This is incorrect because the man says that the man in the photograph’s father is his father’s son. This means that the man in the photograph is the man’s nephew, not the man’s father.
E. None of these: This is incorrect because the photograph is of the man’s nephew.