What are Jared Diamond’s and Harris’s arguments on why stratified societies are still necessary today?

Please provide steps and asnwer to the following question in the Business Analytics Data Analysis and Decision Making 5th Edition by Albright & Winston. Page 333. Conceptual Question 5:

Provide an example of when you might want to take a stratified random sample instead of a simple random sample, and explain what the advantages of a stratified sample might be.

Consider the efforts to repeal Obamacare.

A. What are the common arguments presented to justify repealing Obamacare

B. Are these arguments valid? Explain.

Provide an economic argument for why the government (federal, state) provides so many subsidies to higher education (hint: think about the individual and society at large)