question: Pluto was discovered in 1930 and was named the ninth planet. In 2003, an object larger than Pluto was discovered by astronomer Michael Brown. Pluto has been reclassified as a "dwarf" planet. What does this most likely suggest about scientific investigations?
choices.text: Earlier scientists did not use appropriate tools. Pluto should not have been classified as a planet. Classifications change as new evidence is gathered. Review of planetary characteristics should occur every year.
choices.label: A B C D