29.The following SAS program is sumbitted:
 
  data WORK.INFO;
     infile 'DATAFILE.TXT';
     input @1 Company $20. @25 State $2. @;
     if State=' ' then input @30 Year;
     else input @30 City Year; 
     input NumEmployees;
  run;
How many raw data records are read during each iteration of the DATA step?
 
     A. 1 
     B. 2 
     C. 3 
     D. 4
求解释~