The correct answer is D. standard English conventions.
While you are searching for ideas and content for your text, you will obviously want to take into consideration the uniqueness of ideas (you don't want to copy someone else), relevant support (evidence relevant for your arguments), and explained support (logical evidence that makes sense).
What you don't need to consider when it comes to ideas and content are standard English conventions. This has to do with grammar and your choice of words rather than with the actual content of your text.