When natural disasters are involved, quick timing is key. A siren and a radio announcement would be the fastest way of informing the public of an approaching tornado. Of the rest of the options, a television crawl message would be faster than a newspaper article.
So the media that I would not use to inform the public would be C) A newspaper article.
[tex]\sf\ Answer: {\boxed{\sf\ C)\ A\ newspaper\ article}[/tex]