Concept:The Khalsa was founded by the tenth Sikh Guru, Guru Gobind Singh, in 1699 to create a community of disciplined warrior-saints.Explanation:Guru Gobind Singh instituted the Khalsa on 13 April 1699 (Baisakhi) at Anandpur Sahib. He baptized the first five Sikhs (Panj Pyare) with Amrit, giving them the Five Ks – Kesh, Kangha, Kara, Kirpan, Kachera. This transformed Sikhs into a united force committed to courage, justice, and defending the oppressed. The Khalsa marked a pivotal turning point in Sikh history.Answer:D. Guru Gobind Singh