One of the following is True about K-NN algorithm?
A. In K-NN algorithm there is no need to train the model, all the work done at the prediction time.
B. The mathematical model of the K-NN algorithm makes the training phase very long.
C. The computational cost for the K-NN algorithm is the same for small dataset and large dataset as no training is required.
D. Large value of K will lead always to overfitting issue.