Higher electrical conductivity in acid and bases

I don’t understand c. I thought HCl is stronger than H2SO4… does it got anything to do with first and second dissociation of H2SO4?

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.