b
In this complex, \(2\) 'chloro' ligands and \(2\) 'urea' ligands are present. By following alphabetical order, chloro comes first with its number (i.e., dichloro) followed by the second ligand \(\left( O = C \left( NH _2\right)_2\right)_2\). Since, it is a bidentate ligand (i.e., can attach at more than one binding sites), the prefix 'bis' is used followed by the name of ligand urea. Cu oxidation state will be \(+2(x-2=0)\). So, the correct answer is \(\left[ CuCl _2\left( O = C \left( NH _2\right)_2\right)_2\right]\).