which sentence is true about the main idea of a text?

a.
identifying and evaluating the main idea you understand what you read.

b.
a text may have several main ideas.

c.
main ideas are ideas that do not need support from details.

d.
the main idea will be expressed in the final sentence of expository paragraphs.

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