The correct answer is C. It supports the idea that the burglary was related to politics.
Indeed, the article is about the crime of breaking and entering into the Democratic Party’s offices located in the Watergate Building, by five individuals hired by important members of the Nixon administration and the Republican Party. This context helps interpret their motives and prosecutors surely knew the crime was politically motivated. However, this particular piece of testimony from one of the defendants proves the political motivations of the crime. Nixon pretended initially that this was a common burglary, this statement proves him wrong.
Republican have always been staunch anti-communists/leftists and they have always accused Democrats of being “commie sympathizers”. This type of discourse proves the political affiliation of the burglars.