A weighted graph is a graph G, in which each edge e has been assigned a nonnegative real number w (e), called the weight of e. The weight of a graph is simply defined to be the sum of the weights of its edges. The weight of graph shown above is 1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18= 171.The correct answer is B.