Answer:
(C) opinion statements
Step-by-step explanation:
Formal writings, can be described as a type of writing that is done in a business or academic setting, or other contexts that require the use of formal language.
We can typically ascertain whether a written document is intended for this type of settings based on the language it uses: it tends to use words that you don’t commonly encounter in conversational settings; book language, so to speak. Another characteristic is the complex sentence structure; you would rarely see a sentence where only a subject and verb exists, without being accompanied by other word types. It would also use lengthy descriptions – long winded explanations for things that can actually be summed up shortly.
These things – you would never find in informal writing; however, you will find (C) opinion statements, in informal written communication; such as text messages, chats, and informal letters.