Kavirajamarga is the earliest available writing on poetic and grammar in the Kannada literature. It was written by which of the following King?

Kavirajamarga is the earliest available writing on poetic and grammar in the Kannada literature. It was written by Amoghavarsha King.
Important points about Amoghavarsha:
• Kavirajamarga is the earliest available work on rhetoric, poetics and grammar in the Kannada language.
• It was inspired by or written in part by the famous Rashtrakuta King Amoghavarsha I, and some historians claim it is based partly on the Sanskrit text Kavyadarsha.
• He was the greatest ruler of Rashtrakuta dynasty.
• During the rule of Amoghavarsha-I, many Sanskrit and Kannada scholars gained prominence.
• Amoghavarsha I was a well established scholar and poet.