Answer credited to @Asafmen
It is not stronger than {H_2SO_4}. Both are strong acids, but {H_2SO_4} is diprotic- so even after 100% dissociation, the remains will keep producing more ions.
For the same volume, it would yield a higher ion percentage. That is the only option in which there are 2 strong acids- one of them being diprotic.
Most ions would be produced in such a solution.