The correct option(s) to distinguish nitrate salts of $M{n}^{2+} \mathrm{a}\mathrm{n}\mathrm{d} C{u}^{2+}$ taken separately is(are)

• A

  $M{n}^{2+}$ shows the characteristic green colour in the flame test
• Correct answer
  B

  Only $C{u}^{2+}$ shows the formation of precipitate by passing $H_{2}S$ in acidic medium
• C

  Only $M{n}^{2+}$ shows the formation of precipitate by passing $H_{2}S$ in faintly basic medium
• Correct answer
  D

  $C{u}^{2+}/Cu$ has higher reduction potential than $M{n}^{2+}/Mn$ (measured under similar conditions)

Hence, the correct answer is options: 'B', 'D'.