Litmus is obtained from

Which of the following is a sub-viral agent smaller than a virus?

Which of the following is an exception in the Kingdom Monera?

Which of the following are infectious agents smaller than viruses?

$A.$ The capsid of a virus is made up of many small units called capsomeres.
$R.$ Viruses exhibit active and living behavior in a virus-free state.

Assertion $(A)$: Viruses are considered as a link between living and non-living things.
Reason $(R)$: Viruses are inactive and behave like non-living matter in a free state,whereas they show active and living behavior inside a host cell.