Answer:
A. the BY statement. 
Explanation:
The BY statement aids the procedure MEANS to develop the tree for the current BY group only, thereby analyze the stats, and clean the tree prior to the start and development of the next BY group.
 However, without the BY statement, procedure MEANS develops its AVL tree for both the whole file and all sector estimates crossings established in CLASS.
Hence, in this case, the correct answer is the BY Statement.
 
        
             
        
        
        
Answer:
data source
Explanation:
The main aim of a data source is for the gathering of all necessary information that is needed to access a data. Since he has used the information to create a pie chart, this means that some data were used for the creation of this pie chart. Hence the information used for the creation of the pie chart is the data source for the information illustrated on the pie chart.