hen, suppose we have an undirected graph that is connected $($i$.$e$.$ there is a path between

every pair of vertices$).$ Provide a criterion $($i$.$e$.$ a test$)$ that can be checked during the

execution of DFS to determine whether or not the graph has a cycle. You must explain why

the result of this criterion is True when the graph has a cycle and False when the graph has

no cycles