The best answer to that would be creating a thorough business plan. It can't be letter B because advertising is to attract customers. it can't be C too since an out of the way location for business is doomed to fail, and it can't be D too since this has nothing to do with investors. it is A because in order for you to attract investors, you have to give them a reason to invest in it. You have to convince them that your business idea is a good one and that they will be able to earn from it.