Write SQL query to solve given problem: To which group does the department with the least amount of workers belong to? Indicate the name of the department as well.. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.GroupName FROM EmployeeDepartmentHistory AS T1 INNER JOIN Department AS T2 ON T1.DepartmentID = T2.DepartmentID GROUP BY T2.GroupName ORDER BY COUNT(T1.BusinessEntityID) LIMIT 1