I believe it means everyone has the right to know what is going on but not everyone should have the right to speak up.
        
             
        
        
        
The appositive phrase is not Maya Lin, like the comment above me stated, but it is B) Chinese-American.
An appositive phrase is usually separated from the rest of the sentence by commas, and it describes the subject, which here is Maya Lin. 
        
                    
             
        
        
        
This would most likely be the climax
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Answer:
I would say B. 
Explanation:
A. the whole passage states that there are some causes and effects about junk food, although it says its ok to eat junk food, it tells about what it could do.