The correct option is A Brine solution decomposes on the application of electricity.
The reaction for Chloralkali process is given as :
2NaCl+2H2O⟶2NaOH+Cl2+H2
The reaction occurring at Anode is given as :
Cl−(aq)⟶12Cl2+e−
while, the reaction taking place at cathode is given as :
Na+(aq)+e−⟶Na/HgNa/Hg+H2O⟶NaOH+12H2
So, chlor-alkali process is used to produce chlorine and sodium hydroxide (caustic soda) by the decomposition of brine solution with the application of electricity.