Guru Gobind Singh is the answer that matches the Bihar-specific fact asked in the question. Guru Gobind Singh, the tenth and last human Sikh Guru, was born in Patna on December 22, 1666. The Patna Sahib Gurudwara (also called Takht Sri Patna Sahib) is one of the five Takhts (holy seats of temporal authority) of Sikhism and is built at the birthplace of Guru Gobind Singh. Guru Gobind Singh is revered for founding the Khalsa Panth in 1699 and introducing the five K's (Panj Kakars) for Sikhs. He spent his early childhood in Patna before moving to Anandpur Sahib. Guru Nanak Dev was the first Sikh Guru and founder of Sikhism; he was born in Nankana Sahib (Pakistan), not Patna. Guru Tegh Bahadur was the ninth Sikh Guru and father of Guru Gobind Singh; he visited Patna but was not born there. Guru Arjan Dev was the fifth Sikh Guru who compiled the Adi Granth. The Patna Sahib Gurudwara draws millions of pilgrims every year, especially during the birth anniversary (Gurpurab) of Guru Gobind Singh. The alternatives Guru Nanak Dev, Guru Tegh Bahadur, Guru Arjan Dev may be valid Bihar-related terms, but they do not satisfy the complete relationship asked here.