Answer:
Due to its larger size
Explanation:
This is due to those planets being much larger than Earth. The larger a planet is, the more gravity that planet has, since gravity is mainly calculated based on the mass and radius of the planet. Also since the pressure deep inside of the planet depends mainly on the gravity of that planet on the surface, this is calculated as the square of the planet's surface gravity. Ultimately, the bigger the planet is the higher the pressure deep inside the planet will be.
