During the qualitative analysis of salt with cation ${\mathrm{y}}^{2+}$, addition of a reagent $\left(\mathrm{X}\right)$ to alkaline solution of the salt gives a bright red precipitate. The reagent $\left(\mathrm{X}\right)$ and the cation $\left({\mathrm{y}}^{2+}\right)$ present respectively are :

• Correct answer
  A

  Dimethylglyoxime and ${\mathrm{Ni}}^{2+}$
• B

  Dimethylglyoxime and ${\mathrm{Co}}^{2+}$
• C

  Nessler's reagent and ${\mathrm{Hg}}^{2+}$
• D

  Nessler's reagent and ${\mathrm{Ni}}^{2+}$

Hence, the correct answer is option: 'A'.