Bases strength question

Question

What is the decreasing order of strength of the bases OH^-, NH2^-,H−C≡C^- and CH3-CH2^- ?

Answer 1

Decreasing order of basic strength: NH2^- >OH^- > CH3-CH2^- > H-C=C^- 
OH- is a conjugate base of H2O and NH2^- is a conjugate base of  NH3. H2O is stronger acid than NH3  so OH^- is a weaker base than NH2^- .
CH3-CH2^-  is an alkane H-C=C^-  alkyne in alkynes S character is more so acidic nature is more.

Comments

Sorry but answer is A