Turnbull's blue is

The coordination number and the oxidation state of the element $E$ in the complex $[E(en)_2(C_2O_4)]NO_2$ (where $en$ is ethylene diamine) are,respectively:

$A$ ligand can also be regarded as

The coordination number of $Cu$ in the complex $[Cu(H_2O)_4]^{2+}$ is:

$A$ group of atoms can function as a ligand only when

Given below are two statements :
Statement $I :$ The identification of $Ni^{2+}$ is carried out by dimethyl glyoxime in the presence of $NH_{4}OH$.
Statement $II :$ The dimethyl glyoxime is a bidentate neutral ligand.
In the light of the above statements,choose the correct answer from the options given below: