The correct answer is D. Supreme
Step-by-step explanation:
The word "sovereign" is a noun and adjective often used to refer to the authority of the government or similar entities. Indeed, the word "sovereign" means a supreme or superior ruler that owns more power and authority than other entities. For example, in states with monarchy form of government, the king and the queen are considered as sovereign. Considering the previous ideas, the word that best identifies "sovereign" is supreme because "sovereign" is used to describe a supreme power or figure of authority.