Correct Answer - D
In the first compound the chirality is due to the presence of the chiral `2^(@)` penty1 carbon chain In the second compound N atom uses `sp^(3)` hybridized orbital to from four sigma bonds to four different ligands The resulting cationic enantiomers are configurationally stable at room temperature because there is no lone pair to permit N inversion In the third compound N inversion requires too high energy of activation because the N in such a small ring cannot attain the `120^(@)` angles required in the TS .
