Concept:
• Sikhism was founded on the teachings of ten successive Gurus, starting from the 15th century.
• The lineage of the ten human Gurus ended with Guru Gobind Singh, who designated the *Guru Granth Sahib* as the eternal Guru.
• While many Bhakti and Sufi saints' hymns are included in the Sikh scripture, they are not counted as part of the lineage of the ten Gurus.
Step 1: Identifying the official Sikh Gurus
Guru Nanak Dev (A) was the founder and the first Guru of Sikhism.
Guru Angad Dev (B) was the second Guru, who standardized the Gurmukhi script.
Guru Arjan Dev (D) was the fifth Guru, who compiled the *Adi Granth* and built the Harmandir Sahib (Golden Temple).
Step 2: Identifying the odd entry
Guru Raidas (also known as Bhagat Ravidas) was a 15th-16th century Bhakti saint and poet from North India. While his verses are highly respected and 41 of his hymns are included in the *Guru Granth Sahib*, he was not one of the ten designated Sikh Gurus. He was a contemporary of Guru Nanak but belonged to the broader Bhakti movement rather than the formal lineage of Sikh Gurus.