The correct option is B Earth
A moon is a celestial object that revolves around a planet in the Solar System. Except Mercury and Venus, all other planets in the Solar System have moons around them. Out of which, the least number of moons are present for Earth. It has only one moon called the Moon.
On the other hand, Mars has two small moons, Neptune has 14, and Saturn has 82 moons according to the recent observations.