Which of the following is optically active?

Among the following,the optically inactive compound is

Stereoisomers which are not the mirror images of one another are called

Which of the following is expected to be optically active?

Which of the following compounds might be useful to the chemist trying to increase the optical purity of the $(d)$ sample?

Solutions of optically active isomers rotate the plane of polarized light in a polarimeter. Match the following columns $(I)$ with $(II), (III)$,and $(IV)$ correctly:

$(I)$ Optical Activity	$(II)$ Form	$(III)$ Sign	$(IV)$ Rotation
$(A)$ Dextrorotatory	$d$	$(+)$	Right
$(B)$ Laevorotatory	$l$	$(-)$	Left
$(C)$ Optically Inactive (Racemic)	$dl$	$(\pm)$	Zero rotation