Arrange the following oxidation states in increasing order

(A) characteristic oxidation state of lanthanoids
(B) most stable oxidation state of Mn in its oxides
(C) most stable oxidation state of Mn
(D) oxidation state of Mn in $MnO_2$

Choose the correct answer from the options given below:

(C), (A), (D), (B)

The correct answer is Option (3) → (C), (A), (D), (B)

 Find oxidation state in each case

(C) Most stable oxidation state of Mn
→ Manganese commonly shows +2 as its most stable state (due to half-filled d⁵ configuration stability after losing two electrons).

(A) Characteristic oxidation state of lanthanoids
→ Lanthanoids predominantly show +3 oxidation state.

(D) Oxidation state of Mn in MnO₂
Let oxidation state of Mn = x
Oxygen = −2

x + 2(−2) = 0
x − 4 = 0
x = +4

(B) Most stable oxidation state of Mn in its oxides
→ Highest oxidation state of Mn in oxides is +7 (as in Mn₂O₇), which is considered most stable among its oxides under suitable conditions.

 Arrange in increasing order

+2 < +3 < +4 < +7

So,
(C) < (A) < (D) < (B)