Optical isomers require chirality in molecules

Steps:

• Identify chiral centers: Look for carbon atoms bonded to four different groups.
• Check for symmetry: Ensure no plane of symmetry exists in the molecule.
• Evaluate each option: Determine if the structure meets chirality criteria for optical activity.
• Select the option with enantiomers: Optical isomers are non-superimposable mirror images.

Why B is correct:

• Compound B has a chiral carbon with four distinct substituents, allowing enantiomer formation per the definition of optical isomerism.

Why the others are wrong:

• A lacks a chiral center due to two identical substituents.
• C has a plane of symmetry, making it achiral.
• D is symmetric or has no stereocenter.

Not enough information: Choices lack structural details.

Final answer: B