Correct answer: D. Chand and Bhairav
Explanation: The direct answer is D: Chand and Bhairav. The Santhal Hul, also called the Santhal rebellion, was a major uprising of the Santhal people in 1855–56 against exploitation by moneylenders, zamindars, colonial officials, and other oppressive forces. The best-known leadership pair was Sidhu Murmu and Kanhu Murmu, and their brothers Chand and Bhairav were also associated with the movement. The fact chain is: identify the revolt as the Santhal Hul; remember the leading brothers Sidhu and Kanhu; add their associated brothers Chand and Bhairav; therefore choose D. Option A, Jatra and Budhu, is not the recognised group of four leaders associated with Sidhu and Kanhu in this question. Option B, Ram Singh and Ajit Singh, refers to different historical contexts and does not complete the Santhal leadership group. Option C, Periyar and Narayana Guru, were important social reformers from another context, not the associated Santhal leaders. Option D is correct because Chand and Bhairav are remembered alongside Sidhu and Kanhu. A useful memory aid is the four-name set: Sidhu, Kanhu, Chand, Bhairav. Do not confuse the Santhal Hul with other tribal revolts or later social reform movements; first identify the event, then recall its leaders.