A. speaker 1
b. speaker 2
c. speaker 3
d. speaker 4

The answer is Speaker 1.

 The issue that needs a response is that there is a Soviet blockade, which led the United States decide to airlift supplies into Berlin. The speaker number 1 believes that the United States is able to protect its allies from Communist aggression without resorting to military conflict, which shows he would mostly agree with that decision. This line of thought suggests solution without any other direct involvement such as prevent or never allow other countries' participation or influence.

question is unclear.

i can't sorry.

post the full question so i can .