The correct answer is B.
During Lyndon B. Johnson's presidency, their was a strict foreign policy of containment. Containment is the idea of stopping the spread of communism into new countries/territories. In this case, all of the aforementioned countries were in jeopardy of becoming communist (due to their political instability and constant changes in power). To ensure that this does not happen, Johnson provides military assistance as well as the help of the CIA to these different countries.