#include <iostream>
#include <algorithm>
using namespace std;
// Tighten constants to save every kilobyte
const int MAXN = 100005;
const int MAXM = 200005; // 2 * edges for two-way roads
const int LOG = 17;
// Static Adjacency List (Uses much less memory than vector)
int head[MAXN], to[MAXM], nxt[MAXM], wt[MAXM], edge_cnt = 0;
void add_edge(int u, int v, int w) {
edge_cnt++;
to[edge_cnt] = v;
wt[edge_cnt] = w;
nxt[edge_cnt] = head[u];
head[u] = edge_cnt;
}
// Binary Lifting Tables
int up[MAXN][LOG];
int mx[MAXN][LOG];
int depth[MAXN];
int root_id[MAXN];
// Simple Queue for Iterative BFS (BFS is easier for memory than iterative DFS)
int q[MAXN];
void bfs(int start_node) {
int l = 0, r = 0;
q[r++] = start_node;
depth[start_node] = 1;
root_id[start_node] = start_node;
up[start_node][0] = start_node;
mx[start_node][0] = 0;
while (l < r) {
int u = q[l++];
// Precompute jump table for this node
for (int i = 1; i < LOG; i++) {
up[u][i] = up[up[u][i - 1]][i - 1];
mx[u][i] = max(mx[u][i - 1], mx[up[u][i - 1]][i - 1]);
}
for (int i = head[u]; i; i = nxt[i]) {
int v = to[i];
if (v != up[u][0]) {
depth[v] = depth[u] + 1;
root_id[v] = start_node;
up[v][0] = u;
mx[v][0] = wt[i];
q[r++] = v;
}
}
}
}
int query_max(int u, int v) {
if (root_id[u] != root_id[v]) return 2e9 + 7;
if (depth[u] < depth[v]) swap(u, v);
int res = 0;
for (int i = LOG - 1; i >= 0; i--) {
if (depth[u] - (1 << i) >= depth[v]) {
res = max(res, mx[u][i]);
u = up[u][i];
}
}
if (u == v) return res;
for (int i = LOG - 1; i >= 0; i--) {
if (up[u][i] != up[v][i]) {
res = max({res, mx[u][i], mx[v][i]});
u = up[u][i];
v = up[v][i];
}
}
return max({res, mx[u][0], mx[v][0]});
}
int main() {
// Fast I/O
ios::sync_with_stdio(false);
cin.tie(NULL);
int N, M, U;
if (!(cin >> N >> M >> U)) return 0;
for (int i = 0; i < M; i++) {
int u, v, t;
cin >> u >> v >> t;
add_edge(u, v, t);
add_edge(v, u, t);
}
for (int i = 1; i <= N; i++) {
if (depth[i] == 0) bfs(i);
}
while (U--) {
int a, b, p;
cin >> a >> b >> p;
if (query_max(a, b) <= p) cout << "Yes\n";
else cout << "No\n";
}
return 0;
}
