Which object relates an entity to itself in an entity-relationship model?

Areflexive relationship(also called aunary relationship) occurs when anentity is related to itself.

Example Usage:

A screenshot of a computer AI-generated content may be incorrect.

CREATE TABLE Employees (

EmpID INT PRIMARY KEY,

Name VARCHAR(50),

ManagerID INT,

FOREIGN KEY (ManagerID) REFERENCES Employees(EmpID)

);

ManagerIDrefers to another employeewithin the same table.

Why Other Options Are Incorrect:

Option A (Repository) (Incorrect):A data storage structure, not a relationship type.

Option B (Relationship instance) (Incorrect):Describesa specific connection between entities, not a reflexive relationship.

Option D (Attribute) (Incorrect):Attributes storecharacteristics, butdo not define relationships.

Thus, the correct answer isReflexive relationship, as it relates an entity to itself.