The correct answer to this open question is the following.
Although there are no options attached we can say the following.
No. The House Committee on Un-American Activities (HUAC) and senator McCarthywere not justified in investigating people who were suspected of being communists.
What Senator McCarthy basically did was to accuse many members of the United States federal government and the US military, but he never showed any valid evic¿dence that supported his accusations.
We are referring to Wisconsin Republican Senator Joseph McCarthy who accused many that many people of supporting Communist activities in the mid-1950s. McCarthy just accused people but never offer a serious argument or proof, so he ended up being a liar and his political career ended.