The correct answer is number 2) presidential scandals.
The terms Teapot Dome, Watergate, and Iran Contra are most closely associated with presidential scandals.
These scandals have been part of the United State Politics during different administrations. For instance, the Teapot Dome scandal happened during the William B. Harding administration, at the beginning of the 1920s. The Watergate scandal happened during the administration of President Richard Nixon. Indeed, he resigned before being impeached by Congress. And the Iran Contra scandal happened in 1885, during the administration of Ronald Reagan.