**Que : 1 . T is a graph with n vertices. T is connected and has exactly n-1 edges, then:**

Explanation

Option 4 is Correct Answer

Acyclic graph is called Tree, It means which connect the all vertices by exactly once.

Theorem :The following are equivalent in a graph T with n vertices.

a) T is connected and contains no cycles.

b) T is connected and has n-1 edges.

c) T has n-1 edges and contains no cycles.

d) T is connected and each edge is a bridge.

e) Any two vertices of T are connected by exactly one path.

f) T contains no cycles, but the addition of any new edge creates exactly one cycles.