In EER modeling, what does “inheritance” mean in the context of a subtype and its supertype?

Introduction / Context:
Inheritance in conceptual modeling mirrors the software concept: specialized types automatically obtain the characteristics of their generalized parent type. Understanding the direction of inheritance is crucial for correct modeling.

Given Data / Assumptions:

• There is a supertype with common attributes and possibly common relationships.
• There are one or more subtypes that refine or extend the supertype.

Concept / Approach:
Inheritance means that every instance of a subtype is also an instance of its supertype, and thus it inherits the supertype’s attributes and participation in supertype relationships. The flow is top down: parent to child, not the reverse.

Step-by-Step Solution:

Verification / Alternative check:
Examples: Employee as a supertype with attributes id and name; SalariedEmployee subtype inherits id and name and adds salary fields.

Why Other Options Are Wrong:

• Supertype inheriting from subtype reverses the logical direction.
• Other options refer to cross-supertype or cross-subtype inheritance, which is not the definition of inheritance here.

Common Pitfalls:
Mixing up attribute location; subtypes should not duplicate supertype attributes, as that risks inconsistency.

Final Answer:
When a subtype entity inherits values of the supertype attribute