#include<iostream>

 #include<vector>

 #include<algorithm>

 using namespace std;

 struct GT_cls   //创建函数对象

 {

 public:

     GT_cls(int t=):a(t){}

     bool operator()(int x)

     {

         return x>a;

     }

 private:

     int a;

 };

 int main()

 {

     int T,N,M;

     cin>>T;

     for(int i=; i<T; i++)

     {

         cin>>N>>M;

         vector<int> eigenval(N);

         for(int j=; j<N; j++)

             cin>>eigenval[j];

         sort(eigenval.begin(), eigenval.end());  //从小到大排序

         int max=;

         for(int j=; j<N-; j++)

         {

             vector<int>::iterator it = find_if(eigenval.begin()+j, eigenval.end(), GT_cls(eigenval[j]+M)); //所选取的几种化合物只要满足最小特征值和最大特征值不大于阈值M即可

             unsigned num = it-(eigenval.begin()+j);

             if(num>max)

                 max = num;

         }

         cout<<max<<endl;

     }

     return ;

 }