Explanation : Ordering the weights, the sequence obtained is
1, 1, 2, 2, 3, 3, 4, 4, 5, 6, 7
Now, in order to obtain minimum spanning tree
using Kruskal's algorithm, we have to add edges
with weights in increasing order such that weight
of the spanning tree is minimum.
In option (D), weights of the edges are 1, 1, 2, 3, 2
which contradicts Kruskal's algorithm.