A Researcher, Tim, Wants to Find Out Whether There Are

A researcher, Tim, wants to find out whether there are any differences in employees' motivation in different departments of a large company. He uses a random sampling method. Which of the following might be a problem with using this method for his particular study?

A) There might be too many people in the sample
B) It might not be generalisable
C) It might not be representative
D) He might not pick out any employees from some departments
E) There might be too few people in the sample