$(1)(6$ points$)$ Based on the training data, implement $5-$fold cross$-$validation $($CV$)$ to select the best KNN model with the smallest CV error from different KNN mod$-$ els under different K values, such as K $=210,190,170,150,130,110,90,70,50,30,10,9,8,7,6,5,4,3,2$and$1.$ WhatistheoptiamlK$$fortheselected model? Based on the selected model, compute the confusion matrices and the mis$-$classification error rates for both the training data and test data, respectively. $($Hint: please refer to sample code $"$cv$-$knn$.$R$"$ in the same "Exams" sub$-$folder of CANVAS Files and certain level of customization is needed. $"$cv$-$knn$.$R$"$ im$-$ plements slide $13$ of lecture $10.$ In your problem, set your random seed as $2024$ when you $($i$)$ split training data into $5$ folds, and $($ii$)$ make predictions using KNN models$)$