Match the entries of column I with appropriate entries of column II and choose the correct option out of the four options given.

(i)-(c), (ii)-(a), (iii)-(d), (iv)-(b)

(i) Oxidation state of Mn in MnO₂ is +4.

MnO₂

x + 2(-2) = 0

x - 4 = 0

x = +4

(ii) Most stable oxidation state of Mn is +2.

₂₅Mn: [Ar]4s²3d⁵

Mn²⁺: [Ar]3d⁵

It contains five unpaired electrons in d-orbital and half-filled d-orbital electronic configuration is stable.

(iii) Most stable oxidation state of Mn in oxides is +7.

In MnO₄^-

x + 4(-2) = -1

x - 8 = -1

x = -1 + 8 = 7

(iv) Characteristic oxidation state of lanthanoids is +3.