Verbal Reasoning - Blood Relation Test - Discussion

It must be option D as we don't know the gender of X.

@All.

As per the given statement.

"She is the only daughter of the father of my mother.
“The father of my mother” refers to X’s maternal grandfather.
“The only daughter of the father of my mother” refers to X’s mother.
Therefore, the person in the photograph is X’s mother.
Determining the relationship between X and the person in the photograph:
Since X’s mother is the person in the photograph, X is the son of the person in the photograph.
In summary, X is the son of the person in the photograph.

Option D is the correct answer.

How? We don't even know the gender of X, we cannot decide whether it is a son or a daughter.

Anyone, please explain to me,

I think Nephew is the answer.

His is used for Y not for X. So, I think the correct answer should be option D.

The answer is B his is used for x not for y.

I also got confused about the gender but by closer look it was written "said to his friend" and HIS implies that he is a male.

Here in this question, x's gender is not determined then how to find the answer?

@All.

Here, it is said that she is the only daughter right; but how can you say that he is a son? please clarify my doubt.