Which of the following statements about the ID3 algorithm are correct?

A. The ID3 algorithm always finds the optimal decision tree, i.e., the decision tree with the minimal depth that can classify all training instances.
B. The ID3 algorithm can only be used in binary classification problems.
C. The ID3 algorithm can be used to find a non-linear classifier.
D. Decision trees can be implemented as a set of if-then-else statements.