Which comparison is correct?

HF is a stronger acid than HCl.

H2S is a stronger acid than HCl.

NH3 is a stronger acid than HF.

PH3 is a stronger acid than NH3.

None of the comparisons are correct.

HF is a weaker acid than HCl, as HCl fully ionizes in water while HF only partially ionizes.

H2S is a weaker acid than HCl, as H2S is a weak acid that partially ionizes in water.

NH3 is not an acid, but rather a base. It can act as a weak base in water.

PH3 is not an acid, but rather a weak base. It can act as a Lewis base by donating its lone pair of electrons.