How does verification of sources prevent media bias?

a.
it explains to the reader the need to use eyewitness interviews.
b.
verification of sources is only necessary when writing a research paper.
c.
by checking source material, presenting both sides of an argument, and utilizing information from experts and multiple sources, a reporter is less likely to present a biased account of an event.
d.
when reporters interview several witnesses, they should only select the interviews that best fit with their opinion of the events, and the reporters should not discuss the opposing side.