Untitled

#include <bits/stdc++.h>
using namespace std;

void MO3TAZOLEQ() {
#ifdef MOATAZOLEQ
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
}

#define ll long long

void solve() {
    int n, r;
    cin >> n >> r;
    set<int> st;
    for (int i = 0; i < n; ++i) {
        int x;
        cin >> x;
        st.insert(x);
    }
    int ans = 0;
    for (auto it = st.rbegin() ; it != st.rend(); ++it) {
        if (*it - ans * r <= 0) break;
        ++ans;
    }
    cout << ans << '\n';
}

int main() {
    MO3TAZOLEQ();
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}