How should you address the input differences in production?

Your team trained and tested a DNN regression model with good results. Six months after deployment, the model is performing poorly due to a change in the distribution of the input data.

How should you address the input differences in production?
A . Create alerts to monitor for skew, and retrain the model.
B . Perform feature selection on the model, and retrain the model with fewer features
C . Retrain the model, and select an L2 regularization parameter with a hyperparameter tuning service
D . Perform feature selection on the model, and retrain the model on a monthly basis with fewer features

Answer: C