Organisms such as grasses and lichens are classified as species in the process of succession. a.
Invasive
c.
Secondary
b.
Pioneer
d.
Primary

In this type of succession, grasses and shrubs are the pioneer species. a group of hardy organisms, such as lichen, found in the primary stage of succession and that begins an area's soil-building modification, thus allowing the ecosystem to invade the area.

Explanation:

it is stable as it is in group 0 which have full outer shells of electrons