A _____ simply makes a statement or expresses an opinion.

The correct answer is Declarative Sentence because, by definition, declarative sentences are used to state facts, convey information, or express regular thoughts.

• Declarative Sentence: This is the correct choice. In English syntax, sentences are functionally classified into four groups: declarative (statements), interrogative (questions), imperative (commands), and exclamatory (exclamations). A sentence that states an opinion or fact is exclusively declarative.


• Incorrect Options:
  
  
  
  • Simple Sentence: This is incorrect. This refers to a sentence's structural layout (containing one independent clause), not its functional purpose of making a statement. A simple sentence can easily be a question or a command.
  
  
  • Complement Sentence / Rome: These are incorrect. 'Rome' is a geographical proper noun, and 'Complement Sentence' is not a standard functional category in English grammar.