Which growth regulators are used in the medium during callus culture?

Fill in the blanks in the given flow chart:

Identify the correct statements from the following:
$(i)$ Embryo culture can be used to develop seedlings from seeds that remain dormant for a long time.
$(ii)$ In embryo culture,the embryo is excised and grown in a culture medium.
$(iii)$ Bean seeds do not contain stored food.
$(iv)$ Rapid clonal propagation is an application of suspension culture.

The technique of parasexual fusion was first discovered by

Arrange the following steps of somatic hybridisation in a correct sequence.
$A$. Digestion of cell walls.
$B$. Isolation of naked protoplasts.
$C$. Fusion of protoplasts to get hybrid protoplast.
$D$. Isolation of single cells from two different varieties of plants.
$E$. Growing of hybrid protoplast to form a new plant.
Choose the correct answer from the options given below:

Which method is used to obtain virus-free plants?