The correct option is C Hydrogen gas is given out at the anode
When electricity is passed through an aqueous solution of sodium chloride (called brine), it results in formation of sodium hydroxide solution. This process is called chlor-alkali process.
The reaction involved is:
2NaCl(aq)+2H2O(l)→2NaOH(aq)+Cl2(g)+H2(g)
Chlorine gas is given out at the anode, and hydrogen gas at the cathode. Sodium hydroxide solution is formed near the cathode.