Consider two separate aqueous solutions: one of a weak acid HA and one of HCl. Assuming you started with 10 molecules of HA in one beaker and 10 molecules of HCl in the other beaker.
What are the major species in each beaker?

The answer is given below:

Explanation:

Strong acids have the ability to dissociate quickly as compared to the weak acids which dissociates slowly and can do that up to a certain level.

HCl is a strong acid and HA as stated in the statement is a weak acid.

So, in the beaker which contains HCl will have:

In the beaker with HA will have:

a is the correct answer