In which of the following Buddhist text, through a dialogue between a King and a disciple of Buddha, the Buddhist attitude towards varna is shown?

Vinaya Pitaka Sutta Pitaka Matanga Jataka Majjhima Nikaya

Majjhima Nikaya

In Majjhima Nikaya, through a dialogue between a King and a disciple of Buddha, the Buddhist attitude towards varna is shown.