Weighted Complete Graph:
A weighted complete graph is a graph where every pair of vertices is connected by an edge, and each edge has a weight assigned to it.

Weight of Edges:
In this graph, the weight of the edge (vi, vj) is given by the formula 2 | i - j |, where i and j are the indices of the vertices.

Minimum Weight:
We need to find the weight of a minimum spanning tree (MST) in this graph. An MST is a tree that connects all the vertices in the graph with the minimum total weight.

Algorithm:
To find the weight of the MST in this graph, we can use Kruskal's algorithm or Prim's algorithm.

Kruskal's Algorithm:
1. Sort all the edges in non-decreasing order of their weights.
2. Initialize an empty set of edges, which will form the MST.
3. Iterate over the sorted edges and add each edge to the MST set if it doesn't form a cycle.
4. Stop when there are n-1 edges in the MST set, where n is the number of vertices in the graph.

Explanation:
In this graph, there are n vertices labeled v1, v2, ..., vn. Since it is a complete graph, there will be n*(n-1)/2 edges.

The weight of an edge (vi, vj) is given by 2 | i - j |. Let's consider two cases:

1. When i < />
- The weight of the edge (vi, vj) is 2(j - i).
- For any vertex vi, there are (n - i) vertices with indices greater than i.
- So, the total weight contributed by vertex vi in the MST is 2(j - i) * (n - i).

2. When i > j:
- The weight of the edge (vi, vj) is 2(i - j).
- For any vertex vi, there are (i - 1) vertices with indices smaller than i.
- So, the total weight contributed by vertex vi in the MST is 2(i - j) * (i - 1).

Weight of MST:
To find the weight of the MST, we need to sum up the contributions from each vertex:
Weight of MST = Σ [2(j - i) * (n - i)] + Σ [2(i - j) * (i - 1)]

Simplification:
By simplifying the above expressions, we can show that the weight of the MST is 2(n-1)(n-2).

Conclusion:
The weight of the MST in this graph is 2(n-1)(n-2), which is equivalent to 2n-2. Therefore, the correct answer is option 'B'.