Answer:- 
Solution:- percent ionization = 
where,
is the equilibrium concentration of product ion and c is the initial concentration of the acid.
Let's plug in the values in the formula:



In general, the acid is represented as HA, the ice table is shown as:

I 0.10 0 0
C -X +X +X
E (0.10 - X) X X
where X is the change in concentration that we already have find out using percentage ionization formula.
![Ka=\frac{[H^+][A^-]}{[HA]}](https://tex.z-dn.net/?f=Ka%3D%5Cfrac%7B%5BH%5E%2B%5D%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
Let's plug in the values in it:

0.003 is almost negligible as compared to 0.10, so (0.10 - 0.003) could be taken as 0.10.


Second choice is the right one.