Which of the following is optically active?

Which of the following compounds is optically active?

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

Given the structures $A$ and $B$,determine the relationship between them.

Which one of the following compounds is optically inactive?

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