A. Scikit-learn (sklearn) is a popular machine learning library for Python. To save a trained sklearn model, you can use the "joblib" module, which is part of the sklearn library. The "joblib" module provides a simple way to save and load Python objects, including trained sklearn models. Saving the model enables you to reuse the model for making predictions on new data, without having to retrain the model from scratch. To save a trained sklearn model using joblib, you can use the "dump" function, which takes two arguments: the trained model object and the filename for saving the model.