Who among the following was the first Mongol Il-Khanid ruler to convert to Islam?

Correct option is C

The first Mongol Il-Khanid ruler to convert to Islam was Ghazan Khan.

Ghazan Khan (reigned 1295–1304 CE) formally converted to Islam in 1295 CE. His conversion marked a significant turning point, making Islam the dominant religion of the Mongol Ilkhanate state in Persia.

Additional Knowledge

Jochi (1): Was the eldest son of Genghis Khan and an ancestor of the Golden Horde rulers, not an Il-Khanid ruler.
Guyuk (2): Was the third Great Khan (Khagan) of the Mongol Empire, ruling from Karakorum, and not an Il-Khanid ruler.
Qublai Khan (4): Was the founder of the Yuan Dynasty in China and the fifth Great Khan, ruling the eastern part of the Mongol Empire, and not an Il-Khanid ruler. He embraced Tibetan Buddhism.