The coordination number of cobalt in the complex $[Co(en)_2Br_2]Cl_2$ is

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:

Which coordination compound from the following has a net negative charge on the complex ion?

Ethylenediamine $(en)$ is a:

Which among the following is a monodentate ligand?

Consider the following complex: $[Co(CO_3)(NH_3)_5]ClO_4$.
Mark the correct option for the following parameters in order:
Coordination number $-$ Oxidation number $-$ Number of $d$-electrons $-$ Number of unpaired $d$-electrons.