Reduction is a process wich involves
(i) decrease in the oxidation number of one fo the atoms
(ii) loss of oxygen or an electronegative element
(iii) addition of hydrogen or an electropositive element .
(iv) gain of electrons .

Options

A. (i), (ii), (iiii), (iv)
B. (i), (ii) (iii)
C. (ii), (iii), (iv)
D. (i), (iv)

Answer

A

Explanation

Reduction is a decrease in oxidation number and correspons to a gain, or apparent gain, of electrons (electronation). In biological system, reduction often corresponds to the addition of hydrogen to molecules or polyatomic ions and oxidation often corresponds to the removal of hydrogen.