<u>The correct answer is A. What proof the tipster is able to provide.</u>
The reason why it's anonymous is probably because <em>the person providing the information doesn't feel comfortable providing their identity</em>. That's why we have so many tip lines that assure us we won't be asked for our names, information about where we live or even how we know what we know. All they care about is the information we provide and the accuracy of it.
Hence the correct answer can't be C or D. Just imagine what would happen to the tipster if they are quoted or exposed. They want the crime to stop but they don't want to be harmed for being the people talking about it.
In order to stop the crime or expose it, it is<u><em> necessary</em></u> for the reporter to have <em>concrete evidence</em> of it. Without proof, the reporter won't be able to check if the tip is true. His reputation is also undermined if what he publishes turns out to be fake, so proof is very important.
Answer B it's also incorrect because the <em>intention </em>of the tipster should be <em>irrelevant</em>. Also by stating why they want to talk, they'd be revealing who they are to the criminals (or at least give them an idea) and they wouldn't remain anonymous anymore.
Without a subject and a verb
