Final answer:
The scandal pertaining to Richard Nixon's administration that led to impeachment hearings was known as the Watergate scandal, during which Nixon and his aides were found to have been involved in a cover-up of the break-in at the DNC headquarters.
Step-by-step explanation:
The Watergate scandal is the correct answer to the question regarding the scandal surrounding Richard Nixon's administration that led to impeachment hearings. This political scandal began with the break-in at the Democratic National Committee headquarters at the Watergate office complex in 1972. The ensuing investigation revealed that President Nixon and his aides had been involved in an extensive cover-up. High-profile resignations, indictments, and public hearings ensued. Nixon's own involvement was conclusively proven when he was ordered to release taped conversations from the Oval Office which revealed his knowledge and participation in the cover-up. This led to the House Judiciary Committee passing articles of impeachment and Nixon's subsequent resignation on August 8, 1974, to avoid being removed from office.