Which one of the following does not have $s{p}^2$ hybridized carbon?

* Acetone (${\text{CH}}_3{\text{COCH}}_3$): Carbonyl carbon is $s{p}^2$.Acetamide (${\text{CH}}_3{\text{CONH}}_2$): Carbonyl carbon is $s{p}^2$.Acetonitrile (${\text{CH}}_3\text{CN}$): The nitrile carbon ($C\equiv N$) is $sp$ hybridized, and the methyl carbon is $s{p}^3$. No $s{p}^2$ carbon.Acetic acid (${\text{CH}}_3\text{COOH}$): Carbonyl carbon is $s{p}^2$.