How Many Different $\beta$ -Hydroxyaldehydes And $\beta$ -Hydroxyketones, Including Constitutional Isomers and Stereoisomers, Are Formed Upon Treatment

Multiple Choice

How many different $\beta$ -hydroxyaldehydes and $\beta$ -hydroxyketones, including constitutional isomers and stereoisomers, are formed upon treatment of a mixture of acetone and benzaldehyde with base?

A) 1
B) 2
C) 3
D) 4