Answer:
C
new combinations means variations, and the more the variations there is of a species, the more diverse they are
 
        
             
        
        
        
In my opinion 
Mass extinctions happen because of climate change, asteroid impacts, massive volcanic eruptions or a combination of these causes. One famous mass extinction event is the one that lead to the extinction of dinosaurs, 65 million years ago.
I hope it’s help
        
                    
             
        
        
        
Answer:
The answer to this question is given below in this explanation section.
Explanation:
                     "Alternation of generation"
Alternation of generations is the type of life cycle that occurs in those plant  and algae in the archaeologist and the heterokontophyta that have distinct haploid sexual and diploid asexual stages.In these groups a multicellular haploid gametophyte with n chromosomes alternates with a multicellular diploid sporophyte with 2n chromosomes made up of n pairs.A mature sporophyte produces haploid spores by meiosis a process which reduces the number of chromosomes to half from 2n to n.
Two haploid spores germinate and grow into a haploid gametophyte.At maturity ,the gametophyte produces gametes by mitosis which does not alter the number of chromosomes.Two gametes from different organism of the same species fuse to diploid zygote,which develop into a diploid sporophyte . This cycle from gametophyte to sporophyte in the way in which all land plant and many algae undergo sexual reproduction.