The correct answer is D) Republicans gained control of both houses of Congress.
The event that contributed to Joseph McCarthy’s rise to power during the early 1950s was "Republicans gained control of both houses of Congress."
That event strengthened the power and presence of Wisconsin Republican Senator Joseph McCartney. In the middle of the Cold War years, this Senator accused many people that worked in the US government and the military, to be involved in Communist activities. He caused so much damage with his many accusations. But the worst part was that he signaled many people with no proof at all. That is why years later he lost all of his credibility and ended his career in politics.