Choice C is the best answer. The previous question asks what expectation traditional authorities now face, with the answer being that they must make their perspectives or beliefs clear to the audience. This is supported in lines 33-38("As part...decisions"): "As part of the general process of the transformation of authority... the demand has been for all authority to make explicit the frames of value which determine their decisions."
Choices A, B, and D are incorrect because the lines cited do not support the answer to the previous question about what expectation traditional authorities now face, instead contrasting private and public knowledge (choice A), explaining the complexity of news dissemination (choice B), and providing one way news has changed in modern times (choice D).