Exhibit 19-2 Consider the Data Below to Answer the Following Question(s)

Multiple Choice

Exhibit 19-2
Consider the data below to answer the following question(s) .
Cyanohydrins are important intermediates in the synthesis of α-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.Unfortunately,when a cyanohydrin is treated with aqueous base the original carbonyl compound is isolated.
-Refer to Exhibit 19-2.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