What is a spanning tree in the context of graph theory?
A) A subgraph that includes all the vertices of the original graph and has the minimum number of edges to connect them without any cycles.
B) A subset of the original graph that includes only the vertices with the highest degree.
C) A subgraph that includes all the vertices and edges of the original graph with no repeated edges.
D) A complete graph that connects all vertices with the maximum number of edges.