A volcanic eruption destroyed a forest, covering the soil with volcanic ash. For many years, only small plants could grow. Slowly, soil formed in which shrubs and trees could grow. These changes are an example of Select one: a. equilibrium
b. evolution of a species
c. manipulation of genetics d. ecological succession​

d. ecological succession

Explanation:

Ecology Succession may be initiated either by formation of new, unoccupied habitat, such as from a lava flow or a severe landslide, or by some form of disturbance of a community, such as from a fire, severe windthrow, or logging.

Reference:

Wikipedia contributors. "Ecological succession." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 10 Mar. 2021. Web. 23 Mar. 2021.

b. read the phase at the intersection of any given temperature and pressure.

a physical change is being made.