已知某MySQL 数据库中，有表及其字段如下：Employee（员工）表，字段：ID（标识，主键）、Name（姓名）、DepartmentID（班级标识，外键）Department（部门）表，字段：ID（标识，主键）、Name（名称）要查询所有空部门，可以使用的查询语句是（）。

A.SELECT。FROM Department LEFT JOIN Employee ON Department.ID =Employee.DepartmentID AND Employee.DepartmentID =NULL
B.SELECT。FROM Department LEFT JOIN Employee WHERE Department.ID =Employee.DepartmentID AND Employee.DepartmentID IS NULL
C.SELECT。FROM Department LEFT JOIN Employee ON Department.ID =Employee.DepartmentID WHERE Employee.DepartmentID IS NULL
D.SELECT。FROM Department LEFT JOIN Employee ON Department.ID =Employee.DepartmentID AND Employee.DepartmentID IS NULL