Which of the following is a property of a complete bipartite graph 𝐾𝑚,𝑛K m,n​ ?A. It is planar for all 𝑚m and 𝑛nB. It has 𝑚+𝑛m+n verticesC. It has 𝑚𝑛mn edgesD. It is regular for all 𝑚m and 𝑛n

A complete bipartite graph 𝐾𝑚,𝑛 has the following properties:

A. It is not planar for all 𝑚 and 𝑛. A complete bipartite graph is planar only if 𝑚 ≤ 2 or 𝑛 ≤ 2.

B. It has 𝑚+𝑛 vertices. This is because a bipartite graph is a graph whose vertices can be divided into two disjoint sets such that every edge connects a vertex in one set to a vertex in the other set. So, if one set has 𝑚 vertices and the other set has 𝑛 vertices, then the total number of vertices is 𝑚+𝑛.

C. It has 𝑚𝑛 edges. This is because in a complete bipartite graph, every vertex in one set is connected to every vertex in the other set. So, if one set has 𝑚 vertices and the other set has 𝑛 vertices, then the total number of edges is 𝑚𝑛.

D. It is not regular for all 𝑚 and 𝑛. A graph is regular if every vertex has the same degree. In a complete bipartite graph, the vertices in one set have degree 𝑛 and the vertices in the other set have degree 𝑚. So, the graph is regular only if 𝑚 = 𝑛.