Identify the diagram that best represents the relationship among the given classes:
Earth, Saturn, Planet, Star

Let's analyze the logical hierarchy and grouping among the given classes:
Both Earth and Saturn are separate celestial bodies, but both belong completely to the category of Planets. Thus, two separate circles representing Earth and Saturn will be entirely enclosed inside a larger circle representing Planets.

A Star is an entirely different class of celestial body with no overlap with planets. Therefore, the circle for Star will stand completely separate from the Planet circle.

This classification matches the configuration where one large circle contains two non-intersecting independent circles inside, alongside a completely detached separate circle.