GATE DA 2024 Q14: Edge type in DFS when explored from nearer vertex

Consider performing depth-first search (DFS) on an undirected and unweighted graph G starting at vertex $s$. For any vertex $u$ in G, $d[u]$ is the length of the shortest path from $s$ to $u$. Let $(u, v)$ be an edge in G such that $d[u] < d[v]$. If the edge $(u, v)$ is explored first in the direction from $u$ to $v$ during the above DFS, then $(u, v)$ becomes a ______ edge.