Which of the following statements regarding aldehyde is not correct?

Question

$\begin{array}{1 1}(a)\;\text{The addition reactions occuring across the C=O bond is nucleophilic type}\\(b)\;\text{The addition reactions occuring across the C=O bond is electrophilic type}\\(c)\;\text{Aldehydes under go addition reactions more readily than ketones}\\(d)\;\text{The addition reactions shown by CO group is catalyzed by acid}\end{array}$