#include <stdio.h>
#include <stdlib.h>
#define N 3000
#define M 3000
#define L 1000000
int *ej[N + 1], eo[N + 1], *eh[N + 1], eo_[N + 1];
void link(int **ex, int *eo, int i, int x) {
int o = eo[i]++;
if (o >= 2 && (o & o - 1) == 0)
ex[i] = (int *) realloc(ex[i], o * 2 * sizeof *ex[i]);
ex[i][o] = x;
}
int dd[N + 1], pp[N + 1], ll[M]; char ans[M];
char used[L + 1]; int kk[L + 1], l_, l1;
void dfs_(int r, int i, int sign) {
int o;
if (dd[i] - dd[r] + l1 <= l_)
kk[dd[i] - dd[r] + l1] += sign;
for (o = 0; o < eo[i]; o++) {
int j = ej[i][o];
dfs_(r, j, sign);
}
}
void dfs(int i) {
int o, p;
dfs_(i, i, 1);
for (o = 0; o < eo_[i]; o++) {
int h = eh[i][o], a, b;
if (dd[i] == l_ - ll[h]) {
ans[h] = 1;
continue;
}
for (p = i; p != -1 && dd[i] - dd[p] <= l_ - ll[h]; p = pp[p]) {
b = l_ - ll[h] - (dd[i] - dd[p]);
if (l1 <= b && used[b - l1]) {
ans[h] = 1;
break;
}
}
if (ans[h])
continue;
b = l_ - ll[h] - dd[i];
if (b > 0)
for (a = 1; a <= b / a; a++)
if (b % a == 0 && (kk[a] > 0 || kk[b / a] > 0)) {
ans[h] = 1;
break;
}
}
for (o = 0; o < eo[i]; o++) {
int j = ej[i][o];
dfs(j);
}
dfs_(i, i, -1);
}
int main() {
int n, m, h, i;
scanf("%d%d%d%d", &n, &m, &l_, &l1), l1++;
for (i = 0; i <= n; i++) {
ej[i] = (int *) malloc(2 * sizeof *ej[i]);
eh[i] = (int *) malloc(2 * sizeof *eh[i]);
}
pp[0] = -1;
for (i = 1; i <= n; i++) {
scanf("%d%d", &pp[i], &dd[i]), dd[i] += dd[pp[i]] + 1;
link(ej, eo, pp[i], i);
}
for (i = 0; i <= n; i++)
if (dd[i] <= l_)
used[dd[i]] = 1;
for (h = 0; h < m; h++) {
scanf("%d%d", &i, &ll[h]), ll[h]++;
link(eh, eo_, i, h);
}
dfs(0);
for (h = 0; h < m; h++)
printf(ans[h] ? "YES\n" : "NO\n");
return 0;
}
