If four different substituents are attached to a carbon center then the center is called a chiral center. Here carbon atom bonded with four different substituents ,i.e. -OH , -H , -CH₃ and Cyclopentyl group hence it is chiral carbon. Compound having same molecular formula but orientation of atom in space is different are called stereoisomer. If two compounds are mirror image to the each other and non superimposable then they are called enantiomers. Here to draw enantiomer, in one chiral compound first make -OH group above the plane and -H below the plane and in other chiral compound, make -OH below the plane and -H above the plane. Both these compounds are enantiomer to each other. 

 If four different substituents are attached to a carbon center then the center is called a chiral center. Here carbon atom bonded with -OH group has four different substituent hence hence it is chiral center. Compound having same molecular formula but orientation of atom in space is different are called stereoisomer. If two compounds are mirror image to the each other and non superimposable then they are called enantiomers. Here to draw enantiomer, in one chiral compound first make -OH group above the plane and -H below the plane and for its mirror image put imaginary mirror right side of compound and then draw it. In second compound stereocenter will remain as it is but position of alkyl chain will reversed.

The other possibility is that make -CH(CH₃)₂ above and H below to the plane similarly as above draw  its mirror image.