Why is T not a minimum spanning tree of G?
Vertices: {A,B,C}

Edges: (undirected)
{A,B,4}
{A,C,3}
{B,C,2}

So basically it's a triangle with the given weights. Starting from A, Dijkstra's algorithm will give you (A,B) and (A,C) but the minimum spanning Tree will give you (A,C) and (C,B).