In acidic medium, ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ shows oxidising action as represented in the half reaction

${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}+{\mathrm{XH}}^{+}+{\mathrm{Ye}}^{-}\to 2 \mathrm{A}+{\mathrm{ZH}}_2\mathrm{O}$ $\mathrm{X}, \mathrm{Y}, \mathrm{Z}$ and $\mathrm{A}$ are respectively are:

• A

  $8, 6, 4$ and ${\mathrm{Cr}}_2{\mathrm{O}}_3$
• B

  $14, 7, 6$ and ${\mathrm{Cr}}^{3+}$
• C

  $8, 4, 6$ and ${\mathrm{Cr}}_2{\mathrm{O}}_3$
• Correct answer
  D

  $14, 6, 7$ and ${\mathrm{Cr}}^{3+}$

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