Respuesta :
I would say that letter D would be written using formal language because it seems to be written using very posh words replacing, normal or boring words
The answer to your question would be that the sentence that is using formal language is the following language: Make a list of items that will be needed to complete the project. That is, your answer would be D.
All the other sentences contain abbreviations, phrasal verbs and word choices which are typical of spoken language. For instance, "chill out", "pick up", "stuff", "y'all" and "hang out".