//```// YF YUSUF
#define Free_open(File) freopen((File".in"),"r",stdin);freopen((File".out"),"w",stdout);
#define YF ios_base::sync_with_stdio(0);cout.setf(ios::fixed);
#define YUSUF cout.precision(0);cout.tie(0);cin.tie(0);
#include <bits/stdc++.h>
using namespace std;
#ifdef YF_CHECK
bool Output=1;
#include "g/debug.h"
//#include "g/bigint.h"
//#include "g/text.h"
#else
bool Output=0;
#define deb(x...) 42
#endif
using ll = long long;
//using ld = long double;
using vll = vector <ll>;
using mll = map <ll,ll>;
using pll = pair <ll,ll>;
using vpll= vector <pll>;
template<class T>T MIN(T&a,T b){a=min(a,b);return a;}
template<class T>T MAX(T&a,T b){a=max(a,b);return a;}
#define revers(a) reverse(all(a))
#define all(a) a.begin(),a.end()
#define sortt(a) sort(all(a))
#define sgr v+v+1,tm+1,tr
#define sgl v+v,tl,tm
#define pb push_back
#define ins insert
#define S second
#define F first
#define int ll
ll BP(ll a,ll b,ll mod=1e9+7){
if(b==0)return 1;
ll q=BP(a,b/2,mod);
return ((q*q)%mod*(b%2?a:1ll))%mod;
}
ll dup(ll a,ll b){return (a+b-1)/b;}
ll f(ll x){return x*(x+1)/2;}
const int mod=998244353;
const int INF=1e18+7;
const int inf=1e9+7;
const int N =1e6+7;
struct edge{
ll to,t,b;
};
struct cmp {
bool operator()(const edge &a, const edge &b) const {
return a.t<b.t;
}
};
vector<edge>g[N];
ll n,S;
ll bfs(ll s,ll f,ll t){
set<edge,cmp>q;
q.ins({s,0,t});
vll d(n+1,INF);
d[s]=0;
while(q.size()){
auto [v,D,nowd]=*q.begin();
q.erase({v,D,nowd});
MIN(d[v],D);
for(auto [to,t,b] : g[v]){
if(d[to]>D+t){
// deb(v,to,D, t,S ,nowd );
if(b>=nowd+t){
// deb(to, D+t, nowd+t);
q.ins({to,D+t,nowd+t});
MIN(d[to],D+t);
}
if(b>=t){
// deb(to,D+t+S-nowd,t);
q.ins({to,D+t+(S-nowd),t});
MIN(d[to],D+t+S-nowd);
}
}
}
}
return d[f];
}
void YF_MAIN(ll TEST){
ll m,q;
cin>>n>>m>>S>>q;
for(int i=1;i<=m;i++){
ll x,y,t,b;
cin>>x>>y>>t>>b;
g[x].pb({y,t,b});
g[y].pb({x,t,b});
}
while(q--){
ll s,f,t;
cin>>s>>f>>t;
cout<<bfs(s,f,t)<<"\n";
}
}
bool TECT=0;
bool CASE=0;
bool OUTP=1;
//ll FACT[N],inv[N],FMOD=1e9+7;
//ll PER(ll n,ll k){return FACT[n] *inv[n-k]%FMOD;}
//ll CNK(ll n,ll k){return PER(n,k)*inv[k ]%FMOD;}
//ll lg[N];
void BEFORE(){
return;
// for(int i=2;i<=200000;i++){
// lg[i]=lg[i/2]+1;
// }
// FACT[0]=inv[0]=1;
// for(int i=1;i<=1e6;i++){
// FACT[i]=FACT[i-1]*i%FMOD;
// inv[i]=BP(FACT[i],FMOD-2,FMOD);
// }
}
signed main(){
if(OUTP){YF YUSUF}
// Free_open("TEST");
cout<<(Output ? "\nYF_OUTPUT:\n\n" : "");
int TEST=1;
if(TECT)
cin>>TEST;
BEFORE();
for(int T=1;T<=TEST;T++){
if(CASE)
cout<<"Case "<<T<<": ";
YF_MAIN(T);
cout<<(T==TEST ? "" : "\n");
}
return 0;
}
//```
