Final answer:
Pluto is classified as a dwarf planet, distinct from terrestrial planets and gas giants. Dwarf planets like Pluto are round celestial bodies orbiting the Sun that haven't cleared their orbital paths. Traditional naming conventions for such objects have expanded from Roman to include other mythologies.
Step-by-step explanation:
Our modern understanding of Pluto is that it is a member of C) Dwarf planets. Pluto, Eris, Haumea, and Makemake are considered icy dwarf planets, which are different from the terrestrial planets like Earth and Mars, and the gas giants like Jupiter and Saturn. The largest Kuiper belt objects known, like Pluto, are categorized as dwarf planets because they are found in the icy region beyond Neptune. According to the International Astronomical Union (IAU), a dwarf planet is a celestial body that is in orbit around the Sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a nearly round shape, is not a satellite, and has not cleared its orbit. Pluto meets the first three criteria but not the fourth, because it shares its orbit with other objects of comparable size. Therefore, in 2006 the IAU reclassified Pluto to a dwarf planet.
Naming Dwarf Planets
Traditionally, planets, including dwarf planets, have been named after mythological gods from various cultures. The naming convention has shifted from focusing solely on Roman mythology to including other mythologies as well. This trend recognizes the diversity of cultural heritage and could continue to be a practice for naming newly discovered objects, fostering a sense of international and intersocietal participation in astronomy.