Chlorine is prepared on a large scale by the

A. electrolysis of concentrated sodium chloride solution
B. action of manganese (IV) oxide on hot concentrated hydrochloric acid
C. action of concentrated tetraoxosulphate (IV) acid on sodium chloride
D. oxidation of concentrated hydrochloric acid with potassium tetraxosulphate (VII)
E. action of dilute mineral acids on bleaching powder

Correct Answer: Option A

A. electrolysis of concentrated sodium chloride solution