Answer:
A) President Nixon was impeached by the House of Representatives.
Step-by-step explanation:
The Watergate Scandal was the event that caused Nixon to resign from the office of the presidency. Even though he did not necessarily order to the members of the Committee to Re-elect the President to break in to the Democratic National Headquarters to steal information, he did try to cover the incident up once he learned about it. Nixon's obstruction of justice and coverup was exposed when the Supreme Court forced him to give over tapes of recorded conversations from the White House.
This was when Nixon resigned. This happened before the House of Representatives had a chance to impeach him officially.