The correct answer is C. Hyperparameter tuning. This process involves adjusting the configuration variables that directly influence the training process, such as learning rate, number of hidden layers, and nodes selection, to optimize model performance within the given constraints.

• A. Cross Validation is incorrect because it pertains to the method of partitioning data into training, validation, and test sets to evaluate model performance.
• B. Regularization is incorrect as it refers to techniques used to prevent overfitting by adding a penalty to the loss function.
• D. Drift detection management is incorrect because it involves monitoring and adjusting the model in response to changes in the underlying data distribution over time.

For further reading, refer to:

• Vertex AI Hyperparameter Tuning Overview
• Hyperparameter Tuning with Bayesian Optimization