Instructions $\alpha$ $\beta$ -Unsaturated Aldehydes and Ketones Can Undergo Reaction with Nucleophiles at Reaction

Multiple Choice

Instructions: $\alpha$ , $\beta$ -Unsaturated aldehydes and ketones can undergo reaction with nucleophiles at the $\beta$ carbon, as shown below. Use this information to answer the following question(s) .
-Refer to instructions. This reaction is called a(n) _____ reaction.

A) conjugate addition.
B) electrophilic addition.
C) direct addition
D) 1,2-addition.