GWD-5-22 数学 请教

A certain company assigns employees to offices in such a way that some of the offices can be empty and more than one employee can be assigned to an office.  In how many ways can the company assign 3 employees to 2 different offices?

A.    5

B.     6

C.     7

D.    8

E.     9

D

当一个office空着时，2种

当两个office都满时，C31*A22=6种

8

种