Final answer:
The gas giant, or Jovian planets, are Jupiter, Saturn, Uranus, and Neptune. They are immense and mainly composed of hydrogen and helium, with different atmospheric and interior properties compared to the terrestrial planets.
Step-by-step explanation:
The gas giant, or Jovian planets, are d. Jupiter, Saturn, Uranus, and Neptune. These planets, named after Jupiter (also known as Jove from Roman mythology), differ markedly from the terrestrial planets. They are immense in size, with Jupiter alone being so large that more than 1300 Earths could fit inside it. These giant planets don't have solid surfaces; instead, they consist predominantly of hydrogen and helium, with Jupiter and Saturn having atmospheres rich in ammonia ice particles and various colorants, while Uranus and Neptune have colder atmospheres and methane ice clouds.
The interiors of Jupiter and Saturn are so dense that hydrogen is compressed into a liquid state, subsequently leading some to refer to Jupiter and Saturn as liquid planets due to the liquefied hydrogen. However, the term 'gas giants' is still commonly used. Uranus and Neptune contain more compounds of carbon, nitrogen, and oxygen, and thus sometimes they are also called 'ice giants.'