$3{\mathrm{Br}}_2+6{{\mathrm{CO}}_3}^{2-}+3{\mathrm{H}}_2\mathrm{O}⟶5{\mathrm{Br}}^{-}+{{\mathrm{BrO}}_3}^{-}+6{{\mathrm{HCO}}_3}^{-}$

Which of the following statement says the above reaction is a disproportionation reaction?

Which of the following statements is/are true:
I. The process of oxidation leads to the gain of electrons.
II. The process of oxidation leads to the loss of electrons.
III. The process of reduction leads to the gain of electrons.
IV. The process of reduction leads to the loss of electrons.

Select the correct answer from the codes given below.

Which of the following causes the rusting of iron?
I. Oxidation

II. Reduction
III. Chemical reaction with oxygen.
IV. Chemical reaction with ${\mathrm{CO}}_2$.
Select the correct answer from the codes given below.