The historical figure informing Coleridge's “Kubla Khan, or, a Vision in a Dream. A Fragment” is Kublai Khan. Option C is correct.
Kublai Khan was the fifth Khagan (Great Khan) of the Mongol Empire whose reign protracted from 1260 to 1294 (although due to the division of the empire this was a nominal position). He also founded the Yuan dynasty in China as a conquest dynasty in 1271, and served as the first Yuan emperor until his death in 1294.
"Kubla Khan; or, A Vision in a Dream: A Fragment" is a poem by Samuel Taylor Coleridge.