The option that best describes the cause-and-effect structure in a memoir is when the structure focuses on an incident and its consequences.
I would say that the correct option is the third one.
The cause is the incident, and the effect are its consequences.
        
                    
             
        
        
        
A sentence needs an capital letter, correct grammar and punctuation marks.
 
        
                    
             
        
        
        
I would say "c" because he might want to but maybe not its his choice