Octant rule is related to ?

Ans. is 'a' i.e., Spectroscopy Ultroviolet visible spectroscopy (UV-sis) can distinguish between enantiomers by showing a distinct cotton effect for each isomer.UV-sis spectroscopy sees only chromophores, so other molecules must be prepared for analysis by chemical addition of a chromophores such as antracene.Two methods are repoed : the octant rule and the excition chirality method.