Answer:
The axonal membrane (place as brainliest so others know its correct) 
 
        
             
        
        
        
Answer: A 
Explanation: It makes the most sense because it isn't directly speaking about something, it is mainly summarizing the main idea. I'm not 100%, but that's the one I would choose if it were me. Hope I helped out a little!
 
        
             
        
        
        
Asynchronous Learning is when each student works at their own pace, and may not collaborate on work in class meetings, so the correct answer here would be D!