The correct answer is A) an aerial photograph that shows the Soviet Union's missile sites in Cuba.
You forgot to attach the excerpt. Without it, we do not know exactly what you are talking about.
However, trying to help we did some research and can say that you are referring to the Cuban Missile Crisis of October 1962.
So, if that is the case, the type of media that would best help readers
understand the information in the excerpt is "an aerial photograph that shows the Soviet Union's missile sites in Cuba."
This kind of media would help the readers to have a clear picture of the area of conflict and the closeness to the Florida Peninsula, which was one of the reasons the federal government was very concerned about this issue.
This incident was another chapter in a long series of differences between the United States and the Soviet Union during the Cold War years in which both nations competed in the arms race, the space race, and the spread/containment of Communism around the world.