—Look at the girl with a pair of glasses over there. Can you tell me ______?

—She is a nurse.

A．who is she

B．who she is

C．what is she

D．what she is

某订单处理系统中，"创建新订单"和"更新订单"两个用例都需要检查客户的账号是否正确，为此定义一个通用的用例"检查客户账户"，用例"创建新订单"和"更新订单"与"检查客户账户"之间是（）

A.包含关系

B.聚合关系

C.泛化关系

D.关联关系