This diagram is a representation of the three circles: The first circle is the set of all objects. The second circle is the set of all circles. The third circle is the set of all objects that are circles. The area where these three circles overlap represents a subset of all objects that are both an object and a circle, which can be represented as "A." A Venn diagram is a diagram that shows all possible logical relations between different sets. It is usually used to show all possible logical relations between two sets.