Secondary succession .
a. is predictable because it always ends in the formation of a climax community.
b. typically begins with lichen or moss colonizing rock.
c. occurs after a fire or flood.
d. requires primary succession to precede it occurs after a volcano spreads lava across a landscape.

C. Occurs after a fire or flood

Explanation: fire destroys majority of different types of trees and plant life. Due to remnant of seeds and roots in the soil after a period of time, these roots and seeds begin to germinate again.

flood ruin farmlands however, because the soil and some plant roots are not entirely washed off, over the course of many years a natural secondary succession can occur and the vegetation that had previously grown there can grow again.

the correct answer is:

a population changes in response to a change in the environment.

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms