Question

The Watergate affair started with __________.

claims that the communists had attacked U.S. ships in international waters off the Gulf of Tonkin

a burglary of offices belonging to the Democratic Party

the impeachment of President Nixon

protests against water pollution

Answer 1

"The Watergate scandal was a major political scandal that occurred in the United States in the 1970s as a result of the June 17, 1972, break-in at the Democratic National Committee (DNC) headquarters at the Watergate office complex in Washington, D.C., and the Nixon administration's attempted cover-up of its ..."
So, what it is basically saying, is that Watergate was a break in at the offices of the Democratic party. Hope this helps :)