C would be the best answer
It is rather important using credible sources during your academic writing and research due to the fact that those sources offer information that is considered to be true and trustable, gaining yourself knowledge and your writing will be more complete in information. If you do not have a credible source, however, during your academic writing you might find some difficulties and of course, your writing may contain many mistakes about the topic you are researching about.
Hope this helped! Xoxo.
