d
(d) Trans configuration is more stable than cis configuration because in cis-configuration the \(H\) groups are thrown closely enough together to cause crowding or repulsion. Again between \(1,2-\) and \(1,3-\) configurations, in \(1-3\), the \(OH\) groups are placed further apart to minimise the repulsion. Hence, more stable is \(1,3 -\) configuration.