Out of the given options, the correct answer is 4) Tamraparni.

To understand why it is the correct answer, let`s analyze each option:

1) Periyar: Periyar is a river in the South Indian state of Kerala. It originates in the Western Ghats and flows westwards into the Arabian Sea. Therefore, Periyar is a west flowing river.

2) Bharatpuzha: Bharatpuzha, also known as the Nila River, is another river in Kerala. It originates in the Anaimalai Hills and flows westwards before joining the Arabian Sea. Similar to Periyar, Bharatpuzha is a west flowing river.

3) Pamba: Pamba is a river in Kerala and is famous as the river where the Sabarimala pilgrimage takes place. It originates in the Peerumedu Plateau and flows westwards into the Arabian Sea. Hence, Pamba is also a west flowing river.

4) Tamraparni: Tamraparni is a river located in the Indian state of Tamil Nadu. It is primarily a east flowing river, originating in the Agastyamalai Hills and flowing eastwards into the Gulf of Mannar. Therefore, Tam