(1) Chancellor Kohl, Governing Mayor Diepgen, ladies and gentlemen: Twenty-four years ago, President John F. Kennedy visited Berlin, speaking to the people of this city and the world at the City Hall. Well, since then two other presidents have come, each in his turn, to Berlin. And today I, myself, make my second visit to your city.

In paragraph one, the speaker refers to President Kennedy's previous visit to Berlin in order to

a
acknowledge the failures of the leaders who visited Berlin in the past

b
establish his own credibility by aligning himself with trusted leaders

c
illustrate the hopelessness of repeated presidential visits to the area

d
provide an overwhelming sense of presidential authority and candor

e
threaten an end to future presidential visits and summits with Berlin