Starting on bare rock, what is the usual ecological succession of organisms?
A) lichens, shrubs, bushes, trees
B) shrubs, grasses, lichens, trees
C) lichens, grasses, trees, shrubs
D) shrubs, lichens, grasses, trees

lichens, grasses, shrubs, trees is the correct ecological succession fro organism. Option C is the right answer.

Explanation:

The sequence of changes in a species which make it useful to make a community or colonization.

The rocks being colonized for the first time by an organism, this organism is termed as pioneer species. In this series given lichens are the pioneer species.

lichens are the microorganisms that colonize the bare rock and starts the soil forming process from the acids they secrete.

primary ecological succession will be as:

lichens inhabit  bare rocks and breakdown the minerals rich material in the rock and die to produce organic material so that new species could be formed as grasses will grow which will become shrub and eventually the tree.

Animals eat those grass, shrub or tree products.

lichens, grasses, shrubs, trees,