Consider the following graph G.
Modified DFS on G applied as follows:
• Starting vertex is ‘p’.
• Vertex is visited based on alphabetic order.
• Vertices are visited in order p, q, r, s, t, v.
• It works same as DFS except the visiting order restriction
What is the number of back edges during the above DFS traversal on G?
a. 2
b. 3
c. 4
d. 5
Explain...how??