Identify the sentence which has a non-defining clause? ,The city where I was born is small. , The book that you lent me is great.

My brother who live in Islamabad, is a doctor.

The book that you lent me is great.

The woman who called you is outside.

None of these

My brother, who lives in Islamabad, is a doctor.

Correction to original sentence: It should be "My brother, who lives in Islamabad, is a doctor." (with commas).
The clause "who lives in Islamabad" adds extra information that is not essential to identify "my brother", making it non-defining.