Which of the following is $NOT$ a characteristic or component of a herbarium?

Which locations can be selected for field studies in the taxonomy of living organisms?

In a herbarium,which of the following balls are placed to protect plant specimens from fungi,insects,and moisture?

......... contain information on any one taxon.

$S$ Statement: Herbaria are generally associated with botanical gardens and educational or research institutions.
$R$ Reason: $A$ botanical garden is a planned collection of trees,shrubs,herbs,climbers,and other living plants brought from different parts of the world for scientific purposes.
$(a)$ Both $S$ and $R$ are true,and $R$ is the correct explanation of $S$.
$(b)$ Both $S$ and $R$ are true,but $R$ is not the correct explanation of $S$.
$(c)$ $S$ is true and $R$ is false.
$(d)$ $S$ is false and $R$ is true.

Which one of the taxonomic aids can give comprehensive account of complete compiled information of any one genus or family at a particular time?