.Which Acid Has the Strongest Conjugate Base?

[Soaring Crane]

Which acid of the following set has the strongest conjugate base?

a. CH4
b. NH3
c. H2O
d. HF

Is this correct?

Any help is appreciated

 

[Borek]

OK.

 

[PPonte]

The acid that has the strongest conjugate base must be the weakest.