Explanation:

- Option 1: Earth

- Earth is the only known planet with liquid water on its surface.

- It supports diverse life forms because of this abundant water.

- Correct answer.

- Option 2: Venus

- Venus has a thick atmosphere but no liquid water on the surface.

- Its surface temperature is extremely high due to a runaway greenhouse effect.

- Option 3: Mars

- Mars has signs of past water and may have frozen water, but no current liquid water on its surface.

- It has been a significant interest for scientists because of its potential past habitability.

- Option 4: Saturn

- Saturn is a gas giant with no solid surface, so liquid water is not present.

- It has many moons, some of which might have subsurface water like Enceladus.