Answer
Add an H+ ion to electronegative atoms (such as O and N) of each compound to get conjugate acids.
Work Step by Step
CH3COHNH2 is the only acid with another resonance form because the positive charge can move to the other oxygen. For NaOH, it is Na+ and OH- in solution (ionic salt dissolves into ions in solution), so the conjugate acid of it will just be H2O. For NaNH2, a similar thing happens. It is Na+ and NH2- and the conjugate acid of NH2- is NH3.
