Actually Welcome to the concept of Physical chemistry, and Stochiometry.
So we balance the equation as,
2Na + Cl2 ===> 2NaCl
The required reaction is as:
2Na+ Cl2 = 2NaCl
2 moles Na = 2×23 g = 46g,1 mole Cl2 = 2×35.5g=71g
Now,71g Cl2 reacts with 46g Na,
Therefore, 67.2g Cl2 reacts with 46×67.2/71= 43.54g Name
The rest Na = (55–43.54)g=11.46g
That means Cl2 is a limiting reactant.
Again,2 moles NaCl=2(23+35.5)g=117g
Then,71g Cl2 produce 117g NaCl
Therefore,67.2g Cl2 produce 117×67.2/71 = 110.74g NaCl
hence the correct option is, b.) 111 g NaCl