Final answer:
Ganymede is the largest moon in the solar system and has the largest relative size compared to its parent planet.
Step-by-step explanation:
Ganymede is the largest moon in the solar system and has the largest relative size compared to its parent planet. It is one of the four largest moons of Jupiter, known as the Galilean moons. Ganymede is even larger than the planet Mercury, and about one-quarter of its surface is similar in age and heavily cratered as Callisto.