10 nodes v1,v2,...,v10
Edges 0 less than |i-j| less than or equal to 2
|1-2|=|2-3|=|3-4|=........=|9-10|=1
Weights
1+2,2+3,.....,9+10
i.e., 3,5,7,9,11,13,15,17,19
|1-3|=|2-4|=|3-5|=|4-6|=.... =|8-10|=2
Weights
1+3,2+4,3+5,......8+10
i.e., 4,6,8,.....18
No other edges can be added to this graph
Now, using Kruskal's algorithm, taking the node with the minimum weight for constructing the minimum cost spanning tree.
i.e., v1-v2(weight-3)
Then v1-v3(4),
Can't take v2-v3 since it makes a circuit...
Adding all the weights..
3+4+6+8+10+12+14+16+18=91
Ans:(B) 91