@BHOJARAM
A and B are always true for any connected DAG. Also, DAG can have an isolated vertex with no edges and can be still connected
Given in the question that no. of edges is greater than 0 and so we have minimum 1 edge. So, there must be atleast two vertices in the graph connected by this edge
Now, if we have a third vertex which is isolated , it will disconnect the graph. So, no. of edges plays a vital role in deciding option C