~ C. Population
Population is all the inhabitants of a particular town, area, or country.
        
                    
             
        
        
        
Answer:
The correct option is <em>3. they break down rock into soil in which plants can grow</em>
Explanation:
When a disaster is such huge that even the soil and organic matter get removed from the place, then the succession that will occur in such kind of place will be termed as primary succession. For example, a volcanic eruption or an earthquake.
On the other hand, if after a disaster some of the organic matter remains on the land, then the succession that will occur will be termed as secondary succession. E.g a succession after fire
In primary succession, the pioneer species will be plants that require less soil such as the lichens. The lichens will break down the rocks into the soil and eventually new species of plants will start to grow on the land.
 
        
             
        
        
        
It should be an igneous rock because it formed by the volcanoes lava cooling down
        
                    
             
        
        
        
Answer:
Phenotype
Explanation:
It's phenotype because a genotype is not a physical trait; a genotype means genes. It's phenotype because it a physical trait you can see. Lets say twins look the same on the outside but on the inside they have completely DNA. This is like how some butterflies look the same with orange wings but one might have a mutation in its genes.