Non$-$recursive DFS is run on the following graph. C is the starting vertex.

Which vertices are in vertexStack before the first iteration of the while loop?

Ex: A$,$ B$,$ C$,$ D$,$ E$,$ F

$($commas between values$)$

After the first iteration of the while loop, vertexStack has: A$,$ D$,$ E$,$ F $($top is A$)$

Which vertices are in vertexStack after the second iteration of the while loop?

Which vertices are in visitedSet after the second iteration of the while loop?