单项选择题
下述程序运行后,变量顺序是?()
data perm.update;
infile invent;
input IDnum $15-19Item $1-13Instock 21-22
BackOrd 24-25;
Total=instock+backord;
run;
A.IDnum;Item;InStock;BackOrd ;Total
B.Item;IDnum ;InStock ;BackOrd ;Total
C.Total;IDnum;Item ;InStock ;BackOrd
D.Total;Item ;IDnum ;InStock ;BackOrd