input: Text: SECOND LANDING By FLOYD WALLACE A gentle fancy for the Christmas Season—an oft-told tale with a wistful twistful of Something that left the Earth with a wing and a prayer. Earth was so far away that it wasn't visible. Even the sun was only a twinkle. But this vast distance did not mean that isolation could endure forever. Instruments within the ship intercepted radio broadcasts and, within the hour, early TV signals. Machines compiled dictionaries and grammars and began translating the major languages. The history of the planet was tabulated as facts became available. The course of the ship changed slightly; it was not much out of the way to swing nearer Earth. For days the two within the ship listened and watched with little comment. They had to decide soon. "We've got to make or break," said the first alien. "You know what I'm in favor of," said the second. "I can guess," said Ethaniel, who had spoken first. "The place is a complete mess. They've never done anything except fight each other—and invent better weapons." "It's not what they've done," said Bal, the second alien. "It's what they're going to do, with that big bomb." "The more reason for stopping," said Ethaniel. "The big bomb can destroy them. Without our help they may do just that." "I may remind you that in two months twenty-nine days we're due in Willafours," said Bal. "Without looking at the charts I can tell you we still have more than a hundred light-years to go." "A week,"
  Question: Why do the aliens believe they have succeeded in saving Earth?
  
   (A) The humans did come to a formal agreement before the aliens left them.
   (B) The humans realized they were not alone in the universe. They dropped all their petty differences to defend themselves against an alien invasion.
   (C) The humans painted many pictures of the aliens to commemorate the historic event of first contact, a sign they will hold to the agreement made.
   (D) The humans were kneeling before the aliens in deference, a sign that they will hold to the agreement made.
  Answer:
output: The humans did come to a formal agreement before the aliens left them.