答案：

Explanation:
Define how features are retrieved at inference: Feature retrieval specification Ensure feature consistency between training and inference: Feature retrieval specification Enable automated feature lookup in production: Feature retrieval specification The feature retrieval specification is the key model-level contract for all three requirements. Microsoft defines it as a portable specification containing the exact list of features associated with a model, including the relevant feature store, feature set, and feature-set version . The same specification participates in both training and inference, making it the connective artifact across the model lifecycle.
During training, the feature retrieval specification is used to obtain the required feature values and generate training data. Microsoft requires the specification to be packaged with the model artifact when the model depends on feature-store features. At online inference time, the scoring script loads this packaged specification, resolves the feature list, and initializes online feature lookup before calling the feature store to retrieve current values.
This also prevents training-serving inconsistencies because the deployed model carries the feature dependencies and specific feature-set versions established during training, rather than relying on manually reconstructed production configuration. Microsoft explicitly states that packaging the retrieval specification with the model minimizes changes between training and inference workflows.
A feature set specification defines feature sources and transformations, a feature set asset provides managed versioning, and materialization precomputes feature values. None of those alone defines the model ' s complete retrieval contract at inference.
Study Guide Reference: Implement machine learning model lifecycle and operations - package a feature retrieval specification with the model artifact and operationalize feature-store-backed models.