Knowledge of an authors culture a reader better understand?

What is the best meaning for obscure in this line from the passage? a) ancient b) dark c) royal d) unknown

What happened when the boy who survived an explosion aboard a steamboat returns to town

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