Among the four planets known as gas giants, Jupiter and Saturn are primarily composed of gas.
These massive planets are predominantly composed of hydrogen and helium, with trace amounts of other elements. Both Jupiter and Saturn lack a well-defined solid surface, and their atmospheres transition gradually into dense and pressurized interiors.
Jupiter, the largest planet in our solar system, exhibits intense storms and a powerful magnetic field. Saturn, known for its iconic ring system, is slightly smaller but shares similar atmospheric composition with Jupiter. In contrast, the other two inner planets, Earth and Mars, are terrestrial planets with solid surfaces and different atmospheric compositions, making them distinct from the gas giants.
The complete question is probably:
Which two out of the four planets are primarily composed of gas?