Pointing to a boy, Anuradha said, "He is the only son of my grandfather's only child." How is the boy related to Anuradha?

Family tree

Let's break down Anuradha's statement:

• "my grandfather's only child" → This refers to Anuradha's father (if her grandfather is paternal) or Anuradha's mother (if her grandfather is maternal). Since it says "only child", it implies that this person is Anuradha's direct parent.
• "He is the only son of [my grandfather's only child]" → This means the boy is the only son of Anuradha's parent.

Therefore, the boy is Anuradha's brother.

Hence, the correct answer is "Option 4."