What does a "real thoroughbred mean"?

You visit two websites about inventions of the 21st century. one has .edu in the url address and the other has .com. which site is more likely to be credible and why? (6 points) select one: a. the .edu site is more likely to be credible because all .com sites are trying to sell you something. b. the .edu site is more likely to be credible because its domain is a university or other school type. c. the .com site is more likely to be credible because all .edu sites are personal college student blogs. d. the .com site is more likely to be credible because its owners review all the content before publishing.