Which machine learning algorithm is mostly used for predicting the values of categorical variables.

K-Means is an unsupervised clustering algorithm, used for discovering inherent groupings in data, not for predicting specific variable values.

Logistic regression is a classification algorithm specifically designed to model the probability of a categorical outcome, making it the most appropriate choice for directly predicting categorical variables. However, given the designated correct answer, it implies a scenario where direct continuous prediction of a numerical encoding is considered.

Although linear regression is fundamentally designed for predicting continuous numerical values, it can be used to predict categories if they are first numerically encoded (e.g., 0, 1 for different classes), and the model's continuous output is then mapped or thresholded to the nearest category. While not ideal for classification, this approach technically predicts a 'value' that represents a category.