Answer: D. He quotes experts.
The way in which the author of the business article tries to show that he is being objective is by quoting experts. By quoting experts, the author attempts to show that the information he is providing is not only based on his personal opinion, but is, in fact, supported by evidence. This evidence is so widely acknowledged that experts on the subject agree with it. This is an effective way to show that he is giving us an objective perspective on the topic.