Random forests are one of the most famous machine learning methods. They are easy to understand, easy to implement and reach good prediction performances even without a hyper-parameter tuning. Which...

Random forests are one of the most famous machine learning methods. They are easy to understand, easy to implement and reach good prediction performances even without a hyper-parameter tuning. Which of the following statements on random forest are correct?

a) The prediction of a classification forest is made by a majority vote of the trees’ predictions.

b) The prediction of a regression forest is the median of the tree predictions.

c) Each single tree in the forest uses only a part of the data available.

d) The training time of a random forest scales linear with the number of trees used.