Answer:
J. Edgar Hoover, the long-time director of the Federal Bureau of Investigation (FBI), was known for his efforts to monitor and suppress radical activities in the United States. While I don't have information on his actions in Oklahoma, I can say that he was concerned about the influence of communist groups on students. In this light, if Hoover was involved in efforts to limit the influence of radical groups in Oklahoma, he might have taken measures such as surveillance, informant networks, investigations, pressure on educational institutions, and propaganda and public relations efforts. It's worth noting that Hoover's methods were controversial and raised concerns about civil liberties.