Which amendment did the Hollywood 10 cite in their refusal to answer the whether they were or were not communists?

The Hollywood 10 cited the First Amendment in their refusal to answer whether they were or were not communists. They argued that their right to free speech and expression protected them from having to disclose their political beliefs. This refusal was part of their broader resistance against what they viewed as an infringement on civil liberties during the Red Scare. Their stance led to significant legal and professional repercussions in Hollywood.