Answer:
[tex]\Large \boxed{\mathrm{\bold{A.} \ Group \ 1}}[/tex]
Explanation:
In covalent bonding, atoms share electrons from their last shell to other atoms to gain stability.
Chlorine has 7 electrons in its last shell, it needs to gain 1 electron to become stable.
Group 1 elements have 1 electron in their last shell, they need to lose 1 electron to become stable.
Group 1 elements can bond with chlorine.
