In Gattermann reaction, a diazonium group is replaced by $\underline{X}$ using $\underline{Y}$. $\underline{X}$ and $\underline{Y}$ are $\underline{X} \quad \underline{Y}$

• Correct answer
  A

  $\mathrm{Cl}^{\ominus} \quad \mathrm{Cu} / \mathrm{HCl}$
• B

  $\mathrm{Cl}^{\oplus} \quad \mathrm{CuCl}_2 / \mathrm{HCl}$
• C

  $\mathrm{Cl}^{\ominus} \quad \mathrm{CuCl}_2 / \mathrm{HCl}$
• D

  $\mathrm{Cl}_2 \quad \mathrm{Cu}_2 \mathrm{O} / \mathrm{HCl}$

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