The answer is B. some of the sample data are missing.
This is because out of the 100 students originally sampled by the government agency, only 88 results were taken. 
Additionally, we cannot fully take A. as the answer because a non-response error happens when sampling units are not interviewed maybe because they were unavailable or unwilling. So B. is the safer answer.
        
             
        
        
        
Step-by-step explanation:
MN=MP+PN
3X+2=5X-18
2X=20
X=10
MP=50
MN=32
NP=18
 
        
             
        
        
        
(N+n)x + 1 =11
Hope this help
        
                    
             
        
        
        
First we put the numbers in order....very important
67,76,76,(82),84,87,93
the median is the middle number....so it is 82