Explanation
Why Correct: Guru Nanak (1469-1539) established Sikhism in the Punjab region, preaching monotheism, equality, and social justice, with his teachings compiled in the Guru Granth Sahib.
Distractor Analysis: Gobind Singh (Guru Gobind Singh) was the tenth and final human Guru who formalized the Khalsa in 1699. Ramdas (Guru Ram Das) was the fourth Guru who founded Amritsar. Hargovind (Guru Hargobind) was the sixth Guru who militarized the Sikh community.
Takeaway: Guru Nanak's successors developed Sikhism into a distinct religious tradition, with Guru Gobind Singh establishing the five Ks (Kesh, Kangha, Kara, Kirpan, Kacchera) as Khalsa symbols.