Comprehensive and Detailed Explanation From Exact Extract:

The best practice for mitigating bias in AI/ML models, according to AWS and responsible AI frameworks, is to ensure that the training data is representative and diverse. If a model demonstrates bias (such as favoring a particular demographic), the recommended, cost-effective approach is to collect additional data from underrepresented groups and retrain (fine-tune) the model with the improved dataset.

A. Include more diverse training data. Fine-tune the model again by using the new data:

“The most effective method to reduce model bias is to curate and include diverse, representative training data, then retrain or fine-tune the model.”

(Reference: AWS Responsible AI, SageMaker Clarify Bias Mitigation)

B (RAG) is unrelated to model fairness or bias mitigation; it’s for grounding LLMs with external knowledge.

C (AWS Trusted Advisor) is for AWS resource optimization/security—not for ML model bias detection or mitigation.

D (Pre-train a new LLM) would be extremely costly and is unnecessary; fine-tuning with better data is much more efficient.