Q15,paper3,J1 3. A vertex cover of an undirected graph G(V, E) is a subset V1⊆V vertices such that

(A) Each pair of vertices in V1is connected by an edge

(B) If (u, v) ∈E then u ∈V1 and v ∈V1

(C) If (u, v) ∈E then u ∈V1 or v ∈V1

(D) All pairs of vertices in V1 are not connected by an edge.

Answer C.