input: Text: DUST UNTO DUST By LYMAN D. HINCKLEY It was alien but was it dead, this towering, sinister city of metal that glittered malignantly before the cautious advance of three awed space-scouters. Martin set the lifeboat down carefully, with all the attention one usually exercises in a situation where the totally unexpected has occurred, and he and his two companions sat and stared in awed silence at the city a quarter-mile away. He saw the dull, black walls of buildings shouldering grimly into the twilight sky, saw the sheared edge where the metal city ended and the barren earth began... and he remembered observing, even before they landed, the too-strict geometry imposed on the entire construction. He frowned. The first impression was... malignant. Wass, blond and slight, with enough nose for three or four men, unbuckled his safety belt and stood up. "Shall we, gentlemen?" and with a graceful movement of hand and arm he indicated the waiting city. Martin led Wass, and the gangling, scarecrow-like Rodney, through the stillness overlaying the barren ground. There was only the twilight sky, and harsh and black against it, the convoluted earth. And the city. Malignant. He wondered, again, what beings would choose to build a city—even a city like this one—in such surroundings. The men from the ship knew only the surface facts about this waiting geometric discovery. Theirs was the eleventh inter
  Question: The explorers note the metal band around the city and assume that it is there for defense.  What is ironic about the way they opt to proceed?
  
   (A) They decide to leave the city even though the defense mechanism has not worked for millions of years.  Had they gone on, they would have been rich beyond their wildest dreams.
   (B) They do not believe that the defense mechanism will be engaged, so they venture on.
   (C) They feel that even though the city could be defended, they do not feel that it will match the defenses they bring with them, thus proceeding.
   (D) They become afraid that they will be attacked even though this planet has been abandoned for millions of years.
  Answer:
output: They do not believe that the defense mechanism will be engaged, so they venture on.