Object relationships in software design — which construct implements a “Has a” relationship?

Introduction / Context:
In object-oriented design, relationships between entities are described using specific mechanisms. The “Has a” relationship means one object owns, contains, or aggregates another object.

Given Data / Assumptions:

• We are mapping conceptual relationships to language-agnostic design constructs.
• Terminology: containership includes composition and aggregation.

Concept / Approach:
“Has a” corresponds to composition or aggregation (containership). A car “has a” engine; a university “has” departments. The owner object holds references/fields of the component type.

Step-by-Step Solution:

Verification / Alternative check:
Class diagrams: a filled diamond (composition) or hollow diamond (aggregation) from whole to part is the standard notation.

Why Other Options Are Wrong:
They describe other OO concepts not matching ownership semantics.

Common Pitfalls:
Confusing inheritance (“is a”) with composition (“has a”).

Final Answer:
Containership (composition/aggregation)