The following SAS program is submitted:
data work.staff;
JobCategory= 'FA';
JobLevel= '1';
jobCategory= JobCategory || JobLevel;
run;
Which one of the following is the value of the variable JOBCATEGORY in the
output data set?

A. FA
B. FA1
C. FA 1
D. ' ' (missing character value)

为什么答案是A?