The Major Problem for Human Resource Departments When Dealing with the Variety

The major problem for human resource departments when dealing with the variety of published wage and salary surveys can be that

A) despite similar titles,analysts cannot always be certain that their jobs actually match those being reported
B) the surveys are usually biased toward management level jobs
C) the surveys are often biased towards industrial and less skilled jobs
D) the surveys are usually unreliable
E) it is too costly to subscribe to the reports