Only Cu2+ shows the formation of precipitate by passing H2S in acidic medium.
Only Mn2+ shows the formation of precipitate by passing H2S in faintly basic medium.
Mn2+ shows the characteristic green colour in the flame test.
Cu2+/Cu has higher reduction potential than Mn2+/Mn (measured under similar conditions).
(A) Cu2+ and Mn2+ both give green colour in a flame test, thus cannot be distinguished.