“…[The} military options moved further toward a much larger strike which would very likely have to be accompanied by a land and sea invasion… Almost certainly [an invasion of Cuba] would have led to a Soviet military response somewhere in the world. Now before I leave this question, let me go back and say there was one other military alternative which was considered at the time, and that was a quarantine [blockade], and that of course is what the President decided on. It was believed that this would be seen by Khrushchev not in a sense as a military action, but as a message. It was meant to convey the President’s determination to see those weapons removed…” -Robert McNamara, former Secretary of Defense, interview 1998

Use the passage to answer the question.
Based on the quote, what can best be inferred about why the United States felt it needed to take the action McNamara mentions, as a response to the placement of weapons in Cuba?
A. The threat of an attack on U. S. soil was imminent based on Cuba’s close proximity.
B. The president wanted to send a clear message to the Soviet government.
C. The U. S. government wanted to easily take over nuclear missile operations in Cuba.
D. The Secretary of Defense wanted to prevent the Soviet invasion of Cuba.