Which of the following reactions are disproportionation reactions?
`(A)" " Cu^(+)rarrCu^(2+)+Cu`
`(B)" "3 MnO_(4)^(2-)+4H^(+)rarr2MnO_(4)^(-)+MnO_(2)+2H_(2)O`
`(C )" "2KMnO_(4)rarrK_(2)MnO_(4)+MnO_(2)+O_(2)`
`(D)" "2MnO_(4)^(-)+3Mn^(2+)+2H_(2)O rarr5MnO_(2)+4H^(+)`

Options

A. (A) and (D) only
B. (A) and (B) only
C. (A), (B) and (C)
D. (A), (C) and (D)

Answer

B

Explanation

Disproportionation reaction : The reaction in which same element/compound get oxidized and reduced simultaneously.
(A) `2Cu^(+) rarr Cu^(2+) +Cu^(0)`
(B) `3MnO_4^(2-)+4H^(+)rarr2MnO_4^(-)+MnO_2 +2H_2O`
(D) Option belongs to comproportionation reaction.