Verbal Reasoning - Blood Relation Test - Discussion

I am not getting this, please anyone explain me the answer clearly.

@All.
went deeper to solve this one.
Firstly,
Step-by-step Breakdown:
"My uncle"→ Could be father's brother or mother's brother.

"Father of my uncle"→ That’s your grandfather (on either maternal or paternal side).

"Daughter of the father of my uncle"
→ That means: daughter of my grandfather
→ She could be My mother OR my aunt (if grandfather had multiple children)

"Son of the daughter of the father of my uncle"
→ That’s: son of my mother → my brother
OR
→ son of my aunt → my cousin.

So, what’s the correct interpretation?
The girl is not saying "my mother", but is going indirectly through: Daughter of the father of my uncle

Which could refer to:

Her mother, if her mother is the daughter in question

Her aunt, if her aunt is the daughter in question

But the girl does not specify that the daughter is her mother, so it could be any daughter of the grandfather.

Thus, the most general and safest assumption is that the daughter is the girl’s aunt, making the boy her cousin.

So, the Final Answer: Cousin.

I think the boy is a cousin of the girl.

Agree, A is the correct answer.

Yes, the answer is brother or cousin.

@All

Here if it's mentioned the Girl's mother is the only daughter of her father so that we could get brother as the answer. Here the original answer would be data insufficient or cannot be determined.

According to me, Both cousin and brother are correct.

Let's break down the statement:

"He is the son of the daughter of the father of my uncle."

"Father of my uncle" - This refers to the grandfather.
"Daughter of the father of my uncle" - This is the father's sister, which means the girl's father's sister.
"Son of the daughter of the father of my uncle" - This is the son of the girl's father's sister.

So, the boy is girl's cousin.

He is the cousin of the girl; as he is the son of his father's sister!

According to me, brother is the right answer.