The first graph is bipartite, which can be seen by labeling it as follows.

$A graph with five vertices. Four vertices make up the corners of a diamond; the last vertex is in the center. Edges form the perimeter of the diamond and connect the center vertex to the two corners on the left and right. The vertices on left and right are labeled A, the three vertices in the center column are each labeled B.$

Two of the remaining three are also bipartite.