This principle suggests that when people can't meet a need at a particular level, they try to meet a need at a lower level.

Thats them looking at something else that needs done. kill 2 birds with one stone

Ifound the exercise on the internet. attached is the list mentioned above.in order for a compound to be considered optically active it can't have any axis or plan of symmetry. the molecule  shouldn't also  be superimposable on its mirror image.with such considerations, the compounds that are optically active are: -third compound on the first image is optically active; -second and third compound from the second image are optically actives.