What is revealed about the narrator in paragraph 6? What is the author's likely purpose for these details?

Consider the title and souce of the following articles. which one is most likely to exhibit a bias? (a) how to roast beef," by the food editor of a magazine (b) americans experiencing greater fatigue than previous generations, " by a harvard researcher (c) "americans' worsening eyesight not related to computer screen usage," by the public relations director of a major computer manufacturer (d) "sharing the burden: a history of cooperation," by a college professor