Choose the option of the correct answerWhich among the following are the rnetal centers in the complex cation and the complex anion, respectively?

a$.C{r}^{3+}$ and $C{o}^{3-}$

c$.C{r}^{3--}$ arid $C{o}^{2-}$

b$.C{r}^{3+}$ and $C{o}^{2+}$

d$.C{r}^{3+4}$ and $C{o}^{3+}$

Which of the following is the systematic name of the compound?

a$.$ Diethylenediamineoxalatochromium$($III$)$ dibromidodichloridodiamminecobaltate$($III$)$

b$.$ Diethylenediamineoxalatochromium$($III$)$ dibromidodichlonidodiamminecobaltate$($II$)$

c$.$ Bis$($ethylenediamine$)$ oxalatochromium$($III$)$ diamminedibromidodichloridocobaltate$($III$)$

d$.$ Bis$($ethylenediamine$)$oxalatochromium$($III$)$ dibromidodichloridodiamminecobaltate$($II$)$