Chemistry - STEREO ISOMERISM Question with Solution | TestHub

Compound (D) does not contain a plane of symmetry (POS) or an axis of symmetry (AOS). Compounds (A), (B), and (C) are symmetric structures that possess an alternating or two-fold rotational axis of symmetry ($C_2$). Compound (D) is a chiral molecule represented in a Fischer projection with different terminal groups ($-$CH₃ at the top and $-$CH₂CH₃ at the bottom). Because the two ends of the carbon chain are entirely different, it is impossible to find any plane or axis that splits or rotates the molecule into an identical orientation.

Correct Option: (D)