The correct answer is: " people felt a pressure to conform to avoid suspicion".
Joseph McCarthy (1908 – 1957) served as a Republican US Senator who served on behalf of Wisconsin from 1947 until his death in 1957. He became specially visible in public affairs during the emergence of the tensions against communism and the Soviet Union after WWII, during the so-called Red Scare.
He constantly warned that many communist spies from the URSS had been introduced in the US institutions, in the federal goverment, in the universities, etc. He performed smear campaigns against certain personalities that he considered suspicious for supporting comunism(that were censured by the Senate) and many other anti-communist activities that were grouped under the denomination "McCarthyism".