Answer :
Identifying your audience will help you determine all of the following except "D. appropriate length" The length of a speech/writing can only be determined by other factors.
D. Appropriate length The length is not determined by identifying your audience. You must identify your audience to know how to word your paper or speech and how to use appropriate examples and tone. You would not use the same words and examples for a 5 year old that you would for a 22 year old.