#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cfloat>
#include <chrono>
#include <climits>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <unordered_map>
#include <unordered_set>
#include <vector>
using namespace std;

template <class T1, class T2>
ostream& operator << (ostream& out, const pair <T1, T2> p)
{
	out << '(' << p.first << ',' << p.second << ')';
	return out;
}

template <class T1, class T2>
istream& operator >> (istream& in, pair<T1, T2> &p)
{
	in >> p.first >> p.second;
	return in;
}

template <class T>
istream& operator >> (istream& in, vector<T> &v)
{
	for (T &x : v)
		in >> x;
	return in;
}

template <class T>
ostream& operator << (ostream& out, const vector<vector<T>> &v)
{
	for (const vector<T> &x : v)
		out << x << '\n';
	return out;
}

template <class T>
ostream& operator << (ostream& out, const vector<T> &v)
{
	for (const T &x : v)
		out << x << ' ';
	return out;
}

long long gcd (long long a, long long b)
{
	if (b > a)
		swap(a, b);
	return (b ? gcd(b, a % b) : a);
}

using ll   = long long;
using pii  = pair<int, int>;
using pll  = pair<long long, long long>;
using tiii = pair<pair<int, int>, int>;
using vi   = vector<int>;
using vl   = vector<long long>;
using vvi  = vector<vector<int>>;
using vvl  = vector<vector<long long>>;

#define F          first
#define S          second
#define First      first.first
#define Second     first.second
#define Third      second
#define mp         make_pair
#define rep(i,a,b) for (int i = (a); i < (b); i++)
#define per(i,b,a) for (int i = (b); i > (a); i--)
#define all(x)     x.begin(), x.end()
#define ret(x)     return cout << x, 0;
#define throwex    throw runtime_error ("Found the error.");

// const int h = 1000000007;

signed main()
{
	ios::sync_with_stdio(false);
	#ifdef ONLINE_JUDGE
	cin.tie(nullptr);
	cerr.setstate(ios::failbit);
	#endif

	int t;
	cin >> t;
	while(t--)
	{
		int n, k;
		cin >> n >> k;
		vi h(n);
		cin >> h;
		vi mn = h, mx = h;
		rep(i,0,n)
			mx[i] += k - 1;
		mx.front() = h.front();
		mx.back() = h.back();
		rep(i,1,n)
			mn[i] = max(mn[i], mn[i-1] - (k - 1));
		per(i,n-2,-1)
			mn[i] = max(mn[i], mn[i+1] - (k - 1));
		rep(i,1,n)
			mx[i] = min(mx[i], mx[i-1] + (k - 1));
		per(i,n-2,-1)
			mx[i] = min(mx[i], mx[i+1] + (k - 1));
		cerr << mn << '\n';
		cerr << mx << '\n';
		int y = true;
		rep(i,0,n)
			if(mx[i] < mn[i])		
				y = false;
		cout << (y ? "YES" : "NO") << '\n';
	}
}
