The correct options are
A Prithviraj Chauhan was defeated by Muhammad of Ghor in 12th century.
B The first Muslim kingdom in India was established in Ajmer.
C Qutb-ud-din Aibak was the general of Muhammad of Ghor.
Prithviraj Chauhan was defeated by Muhammad of Ghor in the second Battle of Tarain 1192. The first Muslim kingdom in India was established in Ajmer. Qutb-ud-din Aibak, the general of Muhammad of Ghor became the first Sultan of Delhi.