It's really important to know your audience when you start writing something. For example, if you want to write a dystopian novel, usually teens and young adults read such books, so you want to modify your novel and theme a bit to better suit their interest and understanding. You need to decide on which group of readers you want to write for so that you can adjust themes, motifs, characters, etc.
I would say the correct answer is <span>C. The author doesn't use any facts to support such a claim, so it can't be proven. When making this kind of claim, one has to support it with facts, e.g. artists make this or that percent of their income on concerts and commercials, which clearly proves that they don't depend on the money from CDs etc. The options A and B are not correct because they rely on "everyone knows", which is not true, and is also not supported with facts. The D option isn't correct because one doesn't need to know every artist personally to be able to make a claim based on facts.</span>
