A relation that is free of all modification anomalies is in which normal form?

Introduction / Context:
Higher levels of normalization progressively remove sources of redundancy and anomalies. The strongest commonly cited form in theory ensures complete freedom from modification anomalies.

Given Data / Assumptions:

• First normal form removes repeating groups and enforces atomic values.
• Second and third normal forms address partial and transitive dependencies with respect to keys.
• Boyce–Codd and beyond tighten conditions further; domain/key normal form is even stronger.

Concept / Approach:
Domain/key normal form states that every constraint on the relation is a logical consequence of the domain definitions and key constraints. Under this condition, update, insert, and delete anomalies are eliminated in principle.

Step-by-Step Solution:

Verification / Alternative check:
Classic literature acknowledges that domain/key normal form is sufficient to guarantee freedom from all modification anomalies.

Why Other Options Are Wrong:

• First, second, and third normal forms reduce but do not eliminate all possible anomalies.

Common Pitfalls:
Assuming third normal form or BCNF automatically eliminates every anomaly. Edge cases still exist; domain/key normal form is stricter.

Final Answer:
Domain/key normal form