Which of the following combination amongst the four fischer projections represents the enantiomers
$I$ and $II$
$I$ and $III$
$II$ and $IV$
None
The separation of racemic mixture into pure enantiomers is termed as
Total number of secondary amines (Excluding stereo isomer) possible with the molecular formula $C_5H_{13}N$ is
Given Below are Two statement
Which of the following structure is not meso- $2,3$ -butanediol ?