Explanation:

- Option 1: Apharan

This is the correct answer. "Apharan" is the anti-hijacking exercise conducted jointly by the Indian Navy and the Indian Coast Guard. It aims to enhance inter-agency coordination and readiness in response to potential hijacking situations at sea.

- Option 2: Indra

This exercise is not related to anti-hijacking drills. Instead, "Indra" is a joint military exercise conducted between India and Russia, focusing on improving bilateral defense cooperation.

- Option 3: Ekuverin

"Ekuverin" is an annual bilateral exercise between India and the Maldives. It is primarily focused on enhancing military cooperation and interoperability in tackling terrorism and other security threats.

- Option 4: Nagah

This option doesn't relate to a widely recognized joint military or anti-hijacking exercise involving India.