On apex it was all of the above
There were several steps that were taken by Harry Truman to investigate communist influence in the United states. The first step taken was the creation of the Smith Act that prohibited the communist party from teaching their principles in the country. Many stage actors were also arrested due to the fact that they had ties with the communist party.
The answer is C. Battle of Palmito Ranch because Robert E. Lee, the last land action of the civil was took place at Palmito Ranch near Brownsville.