The correct answer is B.
Joseph McCarthy was an American politician most famous for his practice of accusing people of subversion or treason without proper regard for evidence. This policy was used during the Cold War, when many innocent people were accused of spying of collaborating with the Soviets, thus spreading communism in the United States.
Hundreds of Americans were accused of being Communists or Communist sympathizers, they became subjects of aggressive investigations and questioning. Many of these people were totally innocent and this witch hunt destroyed their lives.
