The festival of Durga Puja is observed to celebrate the triumph of Goddess Durga over ________.

Mahishasura

The correct answer is Option (4) - Mahishasura

The festival of Durga Puja celebrates the triumph of Goddess Durga over Mahishasura. Mahishasura, a powerful demon who could shapeshift, was ultimately defeated by Durga, earning her the epithet Mahishasuramardini ("Slayer of Mahishasura"). Durga Puja commemorates this victory of good over evil.