An undirected connected graph has five vertices.

Three of these vertices are of even degree and two of these vertices are of odd degree.

One extra edge is added. It joins two of the existing vertices.

In the resulting graph, it is **not** possible to have five vertices that are

**A.** all of even degree.

**B.** all of equal degree.

**C.** one of even degree and four of odd degree.

**D. ** four of even degree and one of odd degree.