Detailed Explanation:

Bakhtiyar Khilji, a general under Qutb-ud-din Aibak, invaded Bihar around 1200 CE, conquering regions including Magadha and destroying Buddhist monasteries like Nalanda and Vikramashila. His conquest marked the beginning of Turk rule in Bihar.

Ibrahim, Dariya Khan Noohani, and Malik Husamuddin were later administrators or governors but did not establish Turk dominance in the region.

Therefore, Bakhtiyar Khilji was the real founder of Turk rule in Bihar, making Option 1 the correct answer.