By which name is the birthday of Lord Krishna famous?

Janmashtami

The correct answer is Option (3) - Janmashtami

The birthday of Lord Krishna is known as Janmashtami.

Janmashtami is a Sanskrit word that combines "Janma" (birth) and "Ashtami" (eighth day). This is because Lord Krishna is believed to have been born on the eighth day of the dark fortnight (Krishna Paksha) in the month of Bhadra (August-September).