A. proc sql;
Select * from class
Where age<(select stop_age from threshold);
Quit;
B. proc sql;
Modify table class
Delete where age<(select stop_age from threshold);
Quit
C. proc sql;
Delete from class
Where age<(select stop_age from threshold);
Quit;
D. proc sql;
Alter from class
Delete where age<(select stop_age from threshold);
Quit;