In an ERD, what term indicates the maximum number of entity instances that can participate in a given relationship?

Introduction / Context:
Cardinality specifies how many instances of one entity may relate to instances of another entity. Understanding minimum and maximum cardinalities is essential to enforce business rules in database design.

Given Data / Assumptions:

• The question asks about the upper bound in a relationship.
• ERD notation (Crow’s Foot, UML class diagrams) captures both minima and maxima.
• We want the explicit term for the upper bound.

Concept / Approach:
Maximum cardinality expresses the largest number of related instances allowed (e.g., 1, many, or a specific number like 5). Minimum cardinality expresses the least number required (0 or 1 in most designs). These together define participation constraints.

Step-by-Step Solution:

Verification / Alternative check:
Modeling references consistently use “maximum cardinality” for the upper bound.

Why Other Options Are Wrong:
Minimum cardinality: Lower bound, not upper.
ERD: The diagram itself, not the bound.
GEC / Participation degree: Not standard terms for maximum bound in classical ER modeling.

Common Pitfalls:
Confusing optionality (minimum) with multiplicity (maximum) when translating to database constraints.

Final Answer:
Maximum cardinality