Whereas the successful prosecution of the war requires every possible protection against espionage and against sabotage to national-defense material, national-defense premises, and national-defense utilities . . . .

in the door-way, with his head in the room and with a lantern in hand with the most slight ray of light shining from it; so small and opening it so slowly to not disturb the old mans sleep.

i have watched the play of this story last friday.

option 3

explanation:

"the tune the he might never know again." this part build anticipation. dexter got extremely happy by the piano tune. he could see what he was living at that moment in his life throught this feeling. the reader might want to learn more about his happy life. in fact, he called it a state of   'ecstasy'. the fact that he had got in a mood of intense appreciation and that everything about him was extremely bright and glamorous might lead the reader to feel that this state of happiness may not last long. the two parts from the excerpt that exemplify the anticipation are: " the sound of the "; " it was a know again."