B is the correct answer
A prokaryote cell has no distinct nucleus with a membrane and neither does it have other specialized organelle.
In a eukaryotic cell, the genetic material is DNA in the form of chromosomes which are found within a distinct nucleus. 
Examples of prokaryotes Streptomyces soil bacteria (from which streptomycin antibiotic is derived), Escherichia coli bacterium and Streptococcus bacteria (which causes strep sore throat).
Examples of Eukaryotes include protozoa such as amoeba, fungi, plants, animals and generally all  multicellular organisms.
 
        
                    
             
        
        
        
Answer:
200 approximate
Explanation:
depends how many in common
 
        
             
        
        
        
This is true. it is called origin.
        
             
        
        
        
D looks like the oldest one because there is barley anything there. if not then I would do b
        
                    
             
        
        
        
The Cambrian explosion was a period at the Pre-Cambrian boundary of the geologic time scale at 542 Ma. At this boundary, the fossil record shows that animals suddenly appeared in a dramatic radiation of life. A radiation is the relatively rapid development of new types of organisms that derive from a common ancestor. The Cambrian explosion is important because it marks the origination of all major animal groups called phyla.