$.$ Which of the following statements about the gradient boosting decision tree $($GBDT$)$ algorithm are true?

A Reducing the sample ratio of each basic tree helps reduce the variance.

B$.$ Increasing the minimum number of samples used for segmentation helps prevent overfitti

C$.$ Increasing the minimum number of samples used for segmentation may cause overfitting.

D$.$ Reducing the sample ratio of each basic tree helps reduce the deviation.

Nind