Chemistry - STEREO ISOMERISM Question with Solution | TestHub

First pick out the cis-1,4 drawings : (C) is trans (diequatorial), and (D) has the substituents 1,2 (wrong connectivity); (A) and (B) are cis-1,4. Of the two cis chairs, the higher energy one carries the larger group axial : the ethyl group (A-value ~7.5 kJ/mol) costs more axial than $\mathrm{Br}$ (~1.8 kJ/mol). (A) has ethyl axial and $\mathrm{Br}$ equatorial - the highest energy conformation.