Case$-1$: Parent is the root

Suppose the node $$n$\text{'}$s parent $$p is the root node of the trie $(=$p$=$r$),$ and the edge $$r$$n corresponds to the substring: $[],...,[]$s$[$lo$],...,$s$[$hi$].$

$($A$)$ Write down the substring that would correspond to the unique path from the root to the suffix node of $$n$.$