Which statement best distinguishes surrogate keys from natural keys in a Clarity data model?

• A. Natural keys are system-generated and immutable primary keys.
• B. Surrogate keys are system-generated, immutable identifiers used as primary keys; natural keys are business identifiers with real-world meaning but may be unstable.
• C. Surrogate keys carry business meaning and are user-facing.
• D. Natural keys are always immutable and preferred as primary keys.

Answer: (B)

The idea being tested is how surrogate keys differ from natural keys. Surrogate keys are artificial identifiers created by the system, typically numeric and immutable, and used as the primary key. They have no inherent business meaning, which makes them stable targets for foreign key relationships even when business data changes. Natural keys, on the other hand, come from real-world business data and carry meaning in the domain (like a product code or customer ID). Because they are tied to real data, they can change, be incomplete, or be duplicated, making them less stable as primary keys.

That’s why the best description is: surrogate keys are system-generated, immutable identifiers used as primary keys; natural keys are business identifiers with real-world meaning but may be unstable. The other statements mix up which keys carry business meaning, whether they are user-facing, or whether immutability and primary-key suitability apply, making them less accurate.