为自己加油

现有员工表
A，包含员工 id(staff_id).和部门 id(section_id)两字段,部门表
B,包含部门 id (section_id) 和部所在城市(city)两字段，若想要查询该公司每个城市的员工数，以下语句可以实现的是?单选

A.select city, count(staff__id) from A join B on A . section _id = B .section_id group by B . section;
B.select city, count(staff id) from
A,B group by city;
C.select city,count(staff_ id) from A join B where A . section_id=B . section_id group by city;
D.select city,count(staff_id) from A join B on A section_id= B .section_id group by city;