刚看到新题库里的这道题：
The following GAS program is submitted:
data work.empsalary;
set work.people (in = inemp)
work.money (in = insal);
if insal and inemp;
run;
The SAS data set WORKPEOPLE has 5 observations, and the data set WORKMONEY has 7
observations. How many observations will the data set WORK.EMPSALARY contain?
A. 0
B. 5
C. 7
D. 12
Answer: A
答案选A，不是很理解，不应该是B吗？