The speaker mentions the "suitcase" in paragraph two primarily to ?

(2)we come to berlin, we american presidents, because it's our duty to speak, in this place, of freedom. but i must confess, we're drawn here by other things as well: by the feeling of history in this city, more than 500 years older than our own nation; by the beauty of the grunewald and the tiergarten; most of all, by your courage and determination. perhaps the composer paul lincke understood something about american presidents. you see, like so many presidents before me, i come here
today because wherever i go, whatever i do: ich hab noch einen koffer in berlin. [i still have a suitcase in berlin.] (3)our gathering today is being broadcast throughout western europe and north america. i understand that it is being seen and heard as well in the east. to those listening throughout eastern europe, a special word: although i cannot be with you, i address my remarks to you just as surely as to those standing here before me. for i join you, as i join your fellow countrymen in the west, in this firm, this unalterable belief: es gibt nur ein berlin. [there is only one berlin.]

a. show that he is free to leave the city at any time
b. highlight the fact that his audience is not free to travel
c. express the consistency of american concern for berlin
d. provide an example of his desire to visit frequently
e. voice his frustration with the need to visit frequently