有表tab(name varchar(20), id int, sal int)分别表示员工姓名、员工号、薪水，如何查找出薪水第二高的员工的薪水？

A、select max(sal) from tab where sal B、select min(sal) from (select sal from tab order by sal limit 2);
C、select sal from tab order by sal desc limit 1 offset 1;
D、select max(sal) from tab where sal not in (select max(sal) from tab)