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

It is based on information like chromosome number,structure,and behaviour.

Which of the following statements are correct?
$I.$ Plants collected during field studies are pressed and dried on herbarium sheets.
$II.$ The label on the right-hand side of the herbarium sheet contains the scientific name,family,and common name of the plant.
$III.$ Botanical gardens contain collections of plant specimens as well as illustrations,slides,maps,and photographs.
$IV.$ Living plants can be observed and identified in botanical gardens.

Assertion $A$: Botanical gardens provide taxonomic information for research at a single location.
Reason $R$: Botanical gardens contain herbaria and libraries as their main components.
Which option is correct for Assertion $A$ and Reason $R$?

$A$ cryptogram has got how many pairs of information?

Which is the final step used for preserving plant specimens in herbaria?