The answer is C. A variety of antibiotics
        
                    
             
        
        
        
Microevolution refers to changes that occur within a single species or group or organisms.  Microevolution, as opposed to macroevolution, occurs in a short period of time. In microevolution, the ancestor and the descendant obviously belong to the same type.  For example, certain pests have evolved in such a way that they become immune to pesticides; the same thing has happened to certain weeds and herbicides. Hope this helps.
        
                    
             
        
        
        
Answer is <span>c. penicillin </span>
        
                    
             
        
        
        
Answer:
a layer or a series of layers of rock in the ground. , 
a level or class to which people are assigned according to their social status, education, or income.
Explanation: