Review case Ricci v. DeStefano, and answer the following please?

L= 1. What is disparate impact discrimination and how does it differ from intentional (aka, "disparate treatment") discrimination? 2. What is the standard employer defense to disparate impact discrimination? 3. Was that defense available to the City in this case? 4. [Critical Thinking] Based on the Court's analysis and decision, what should a future employer in similar circumstances do to avoid claims of discrimination