Explanation:

- Naharkatia is an oil-rich region located in the northeastern part of India.

- Option 1: Assam

- The Naharkatia oil region is indeed in Assam.

- It is part of the famous Assam Basin where oil exploration began in India.

- Option 2: West Bengal

- West Bengal is not a known oil-producing state.

- The region is more famous for coal and other minerals.

- Option 3: Maharashtra

- Maharashtra has significant oil refineries but not major oil fields.

- The focus is more on energy and port industries.

- Option 4: Gujarat

- Gujarat is an oil-producing state but Naharkatia is not located there.

- It is known for its coastal refineries and gas fields.