secondary succession in an existing ecosystem new species developing in an ecosystem species competition in a community primary succession in a new habitat
I gave my students this multiple choice question: After mining removes layers of rock from a hillside, new plants begin to grow in the cracks of the bare rock. The plants beginning to grow are an example of which natural process?

Only one answer is correct among these 4 choices:
- secondary succession in an existing ecosystem
- new species developing in an ecosystem
- species competition in a community
- primary succession in a new habitat

Could you tell me which one is correct?

primary succession in a new habitat