The following program is submitted:
data work.test;
set work.staff (keep=salary1 salary2 salary3);
<insert ARRAY statement here>
run;
Which ARRAY statement completes the program and creates new variables?
a. array salary{3};
b. array new_salary{3};
c. array salary{3} salary1-salary3;
d. array new_salary{3} salary1-salary3;
Correct answer:  b


我选的D，觉得应该要把变量写出来吧。为什么答案是D呢？请大家帮忙解答一下。谢谢！