Let Rv be the complete bipartite graph Km, n and m + n = v then the chromatic number of Q̅ is _____ ( R̅v is complement of Rv)
1
min (m, n)
2
max (m, n)
3
\(\frac{{v\left( {v - 1} \right)}}{2} - 2\)
4
\(\frac{{v\left( {v - 1} \right)}}{2} - m \times n\)