The First Oxidation in the β-Oxidation of Saturated Fatty Acids

The first oxidation in the β-oxidation of saturated fatty acids is catalyzed by ____ and is the conversion of ____.

A) β-hydroxyacyl-CoA dehydrogenase; a primary alcohol to an aldehyde.
B) acyl-CoA dehydrogenase; a carbon-carbon single bond to a carbon-carbon double bond.
C) acyl-CoA dehydrogenase; a secondary alcohol to a ketone.
D) β-hydroxyacyl-CoA dehydrogenase; an aldehyde to a carboxylic acid.
E) acyl-CoA dehydrogenase; an aldehyde to a ketone.