The correct option is A Zn→Zn2++2e
The reaction at anode in the electrochemical cell is
Zn→Zn2++2e
It is an oxidation reaction
The reaction at cathode in the electrochemical cell is
Cl2+2e→2Cl−
It is a reduction reaction.
In the cell notation, the left hand electrode is anode where oxidation half reaction occurs.
The right hand electrode is cathode where reduction half reaction occurs.