列出所有部门的职工人数(包括没有职工的部门) ()。
A、select dept.deptno,dname,count(emp.empno) from emp,dept where emp.deptno=dept.deptno group by dept.deptno,dname;
B、select dept.deptno,dname,count(emp.empno) from emp,dept where emp.deptno()=dept.deptno group by dept.deptno,dname;
C、select dept.deptno,dname,count(emp.empno) from emp,dept where emp.deptno=dept.deptno() group by dept.deptno,dname;
D、select dept.deptno,dname,count(emp.empno) from emp,dept where emp.deptno()=dept.deptno() group by dept.deptno,dname;