An organization is planning for sampling procedure to apply in their company on-site kindergarten facility. But before taking further steps, it wants to get the reactions of four groups to the idea: (1) Employees who are parents of kindergarten-age children, and where both are working outside of the home, (2) employees who are parents of kindergarten age children, but where one of them is not working outside of the home, (3) single parents with kindergarten-age children, and (4) all those without children of kindergarten age. If the four groups are expected to represent 60%, 7%, 23%, and 10 % respectively, in the population of 420 employees in the company. Requirement What would be appropriate sampling technique to apply to represent four groups, justify your answer?