US leaders believed that Iranian nationalists were too friendly with communists; therefore,

U.S. leaders feared that Iranian prime minister Mohammad Mossadegh’s nationalist government might move closer to communism during the Cold War. In 1953, the United States helped organize a coup that removed Mossadegh and restored Shah Mohammad Reza Pahlavi, the former ruler’s son, to power. So the correct choice is “the United States helped restore the former ruler’s son to power.”

AI-written and checked against the verified answer.