The magnetic observatory which was inaugurated on so” March 2015 is located at

Allahabad
Gulmarg
Shillong
Port Blair

The correct answer is (c) Shillong.

The magnetic observatory which was inaugurated on 20 March 2015 is located at Shillong, Meghalaya. It is the first of its kind in the North-East and is expected to help in studying the Earth’s magnetic field and its changes. The observatory is equipped with state-of-the-art instruments and will be used for research and educational purposes.

The other options are incorrect. Allahabad is a city in Uttar Pradesh, Gulmarg is a town in Jammu and Kashmir, and Port Blair is a city in Andaman and Nicobar Islands.