Deep Learning $($DL$)$ which uses either deep architectures of learning or hierarchical learning approaches is a class of Machine Learning $($ML$).$ Identify the statements correct below.

A$.$ DL approaches do not require precisely defined features.

B$.$ Traditional ML approaches use handcrafted engineering features by applying several feature extraction algorithms, and then apply the learning algorithms.

C$.$ In DL$,$ the features are learned automatically and represented hierarchically in multiple levels.

D$.$ The DL approach is not scalable.