Social structures in society can work to provide an ordering of society from things as diverse as institutions like courts and police forces to schools etc. However, depending on the rigidity of social structures certain groups can also be oppressed or left out of the governing decisions within a society.
The cause for the scandal was the discovery of bribery in the cabinet and the government regarding oil trade. One effect was that it proved that cabinet members are not all powerful and can be arrested and indicted just like anyone. Another effect was the Supreme Court's ruling in McGrain v. Daugherty which explicitly established that Congress had the power to compel testimony. A third effect was that the government was given back the oil fields that were leased and they stayed in US ownership until 2015 when it was legally sold.
I thinks that the answers its D
Reaganomics, Beirut, Russia (I'd argue that through détente and the arms control negotiations, this was achieved), Surgeon-General, Reagan, I'd say true - it's highly debatable, and communism continued for a few more years after its downfall, but ultimately it was the end of the system, and Saudi oil fields.
Merchants in Asian countries were infected with the Black Death, this was then passed on through the cloth that was sold as the cloth was contaminated