At what point does an analyst stop the building and/or pruning process of a decision tree model?
a. Several models with different amounts of pruning are evaluated against the validation sample to find the best model.
b. Several models with different amounts of pruning are evaluated against the training sample to find the best model.
c. Decision trees continue adding branches until all resulting rectangles are pure. This is therefore the perfect model and should be deployed.
d. Decision trees continue adding branches until the Gini impurity reaches a threshold set by the analyst.