Ibadat Khana at Fatehpur Sikri was

The correct answer is C. The Ibadat Khana was a hall built at Fatehpur Sikri around 1575 where Akbar held debates with scholars of Islam (including Sunni, Shia and Mahdawi scholars), Hinduism, Jainism, Zoroastrianism and Christianity. The Jesuit priests from Goa were the most prominent Christian visitors. The purpose was to test the claims of different faiths, and this experience fed into the policy of sulh-i-kul, or peace among all.

• A is wrong: the royal mosque at Fatehpur Sikri is the Jama Masjid. The Ibadat Khana was a debating hall, not a place of worship for the royal family.
• B is wrong: the discussions were open debates among scholars, not Akbar's private devotions.
• D is wrong: the participants were theologians and scholars, not the nobility gathering as a body. Nobles were present, but the defining feature is the scholars.

Core concept: Akbar's religious policy, sulh-i-kul and the Mughal state's accommodation of plural faiths. It links to Mains GS-1 on medieval Indian society and to religious tolerance as a theme in Indian political thought.

Trap: candidates pick D because nobles did attend, or A because the Jama Masjid is the famous building nearby. Remember that the defining feature is debate among scholars of different faiths.