Which logical data model establishes a strict top-to-bottom (tree) relationship where each child has exactly one parent but a parent may have multiple children?

Introduction / Context:
Choosing a data model affects how relationships are expressed and constrained. The hierarchical model organizes records into a tree, enforcing a one-to-many parent–child structure that simplifies certain traversals but restricts lateral relationships.

Given Data / Assumptions:

• Each child record must have exactly one parent.
• A parent may have zero or more children.
• No many-to-many or multi-parent relationships are allowed.

Concept / Approach:

Hierarchical schemas (e.g., IBM IMS) represent data as rooted trees. In contrast, network schemas allow many-to-many via owner/member sets, and relational schemas express relationships flexibly with keys and join tables without enforcing a single-parent rule. Therefore, the described top-to-bottom relationship is characteristic of a hierarchical schema.

Step-by-Step Solution:

Verification / Alternative check:

Legacy mainframe systems and textbooks consistently define hierarchical models by a strict parent–child tree with one parent per child node.

Why Other Options Are Wrong:

Network schema: Supports multiple owners; not a strict tree.

Relational schema: Uses tables and keys; no enforced single parent relationship.

All/None: Do not match the precise description.

Common Pitfalls:

Confusing logical models (hierarchical vs. network) when converting legacy systems to relational schemas.

Final Answer:

Hierarchical schema