The most acidic hydrogen of 4‐hydroxybutanenitrile


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> Identify the most acidic hydrogen atom in the compound below:
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> $$\ce{NC-CH2-CH2-CH2-OH}$$
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My teacher said that the $\ce{H}$ connected to $\ce{O}$ is the most acidic since $\ce{O}$ is more electronegative than carbon.


However, I see that the $\ce{H}$ connected to the carbon adjacent to cyanide must be more acidic since the conjugate base is stabilized by resonance, contrarily to that connected to $\ce{O}$.


Isn't resonance the most significant criterion in determining the stability of a conjugate base? Or does the electronegativity of the donor atom matter more?


