Chemistry - STEREO ISOMERISM Question with Solution | TestHub

A molecule is chiral if it does not possess a plane of symmetry and its mirror image is non-superimposable.

(A) has a vertical plane of symmetry passing through the apex and midpoint of the base, so it is achiral.

(C) also contains a plane of symmetry because the two Br atoms are identical and symmetrically placed; hence it is achiral.

(D) has a center/plane of symmetry and is therefore achiral.

In (B), the cyclopropene ring has three different substituents (Cl, Me, and Et), destroying all symmetry elements. Therefore, its mirror image is non-superimposable.