Instructions: Consider the Data Below to Answer the Following Question(s) $\alpha$

Multiple Choice

Instructions: Consider the data below to answer the following question(s) .
Cyanohydrins are important intermediates in the synthesis of $\alpha$ -hydroxycarboxylic acids from ketones and aldehydes. The nitrile functional group can be hydrolyzed by aqueous acid to yield a carboxylic acid. Nitriles can also be hydrolyzed to carboxylic acids using aqueous base. When a cyanohydrin is treated with aqueous base, however, the original carbonyl compound is isolated.
-Refer to instructions. The reaction of an aldehyde with hydrogen cyanide is an example of _____ reaction.

A) a nucleophilic substitution
B) an electrophilic addition
C) an electrophilic substitution
D) a nucleophilic addition