To determine the number of stereoisomers for 3-chloro-2-hydroxybutanoic acid, we need to identify the chiral centers in the molecule. Chiral centers are carbon atoms that have four different groups attached to them.The structure of 3-chloro-2-hydroxybutanoic acid is as follows:CH3 - CH OH - CH Cl - COOHThere are two chiral centers in this molecule: the carbon with the hydroxyl group C2 and the carbon with the chlorine atom C3 .For each chiral center, there are two possible configurations R and S . Since there are two chiral centers, the total number of stereoisomers is 2^n, where n is the number of chiral centers.2^2 = 4Therefore, there are 4 possible stereoisomers for 3-chloro-2-hydroxybutanoic acid.