You are developing a natural language processing model that analyzes customer feedback to identify positive, negative, and neutral experiences. During the testing phase, you notice that the model demonstrates a significant bias against certain demographic groups, leading to skewed analysis results. You want to address this issue following Google's responsible AI practices. What should you do?

A. Use Vertex AI's model evaluation lo assess bias in the model's predictions, and use post-processing to adjust outputs for identified demographic discrepancies. B. Implement a more complex model architecture that can capture nuanced patterns in language to reduce bias. C. Audit the training dataset to identify underrepresented groups and augment the dataset with additional samples before retraining the model. D. Use Vertex Explainable AI to generate explanations and systematically adjust the predictions to address identified biases.