#include "bits/stdc++.h"
using namespace std;
#define sim template < class c
#define ris return * this
#define dor > debug & operator <<
#define eni(x) sim > typename \
  enable_if<sizeof dud<c>(0) x 1, debug&>::type operator<<(c i) {
sim > struct rge { c b, e; };
sim > rge<c> range(c i, c j) { return rge<c> {i, j}; }
sim > auto dud(c* x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct debug {
#ifdef LOCAL
  ~debug() { cerr << endl; }
  eni( != ) cerr << boolalpha << i; ris;
}
eni( == ) ris << range(begin(i), end(i));
}
sim, class b dor(pair < b, c > d) {
  ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d) {
  *this << "[";
  for (auto it = d.b; it != d.e; ++it)
    *this << ", " + 2 * (it == d.b) << *it;
  ris << "]";
}
#else
  sim dor(const c&) { ris; }
#endif
};
#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
///////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////
#define int long long

void solve() {


  int n, k;
  cin >> n >> k;
  vector<int>a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    a[i] += k;
  }
  int mn, mx;

  mn = a[0] - k + 1;
  mx = a[0] + k - 1;

  for (int i = 1; i < n; i++) {

    int low = a[i];
    int high = a[i] + k - 1;
    debug() << imie(i) imie(low) imie(high) imie(mn) imie(mx);
    if (i == n - 1)
      high = a[i];

    if (high < mn || low > mx) {
      cout << "NO" << endl;
      return;
    }

    mn = max(mn - k + 1, low - k + 1);
    mx = min(mx + k - 1, high + k - 1);

  }



  cout << "YES" << endl;


}

int32_t main() {
  ios::sync_with_stdio(false);
  cin.tie(0);

  int t;
  cin >> t;

  while (t--) {
    solve();
  }


}
