Which refers to connecting entities of different types when identifiers are different?a.Binary relationshipb.HAS-A relationshipsc.Noned.IS-A relationships

The correct answer to the question "Which refers to connecting entities of different types when identifiers are different?" is:

c. Noned. IS-A relationships

Explanation:

1. IS-A Relationships: This type of relationship typically represents a hierarchy or inheritance in object-oriented design, connecting entities where one type is a specialized version of another. For example, a 'Car' IS-A 'Vehicle'. This usually involves the same identifier type, distinguishing entities based on type.

2. Binary Relationships: These involve two entities but do not specifically address the issue of different types or identifiers.

3. HAS-A Relationships: This signifies a composition or association where one entity contains another, usually maintaining identifiers within the same general type.

Since the question emphasizes connecting entities of different types with different identifiers, the most appropriate option would indeed be an IS-A relationship (though the wording of "Noned" is unclear and may be an error in the answer choices).

In conclusion, none of the listed options perfectly fit the description, but IS-A relationships do relate to the way different types can be connected, implying shared or inherited characteristics.