**A connected undirected multi graph has Euler's circuit iff all vertices are of Even degree**

1.**K**_{9,9 }is Bipartite graph with each side having 9 vertices and each of the vertex on one side are connected to all vertices of other side,hence degree of all vertices are 9 which is odd degree**, Therefore No Eulers Circuit**

2 &3 .**K**_{8,8} and K_{12,12}_{ }is Bipartite graph with each side having 8 vertices and each of them are connected to all vertices of other side,hence degree of all vertices are 8 and 12 respectively which is Even**, Therefore Eulers Circuit exists**

4. **K9** Complete graph with 9 vertices with each vertex connected to all other therefore degree is 8,**Therefore Eulers Circuit exists**

**5.**

In this graph also all vertices have even degree. So, Euler circuit exists.

**Hence Option A doesn't have Euler's circuit**