One Halloween a little boy and his friend went out for a fun night of trick-or-treating. At first everything was great. They were getting lots of candy as they went from house to house, but then they saw a house which they hadn't been to before. It was a very spooky   house. Being young and brave, they decided to go up to the door and knock. After all, scary houses might have the best candy! As they walked up the long winding path, they saw things that chilled   them to the bone! They heard sounds that frightened them. Maybe they should turn back. But the little boys, being very brave, just wanted to see what was in that house, so they went on, not deterred by the things they heard or saw. As they slowly made their way up to the door, they imagined what might be inside. Maybe it would be a witch or maybe a ghost! After knocking several times, the door slowly creaked   open. To their surprise, a monster   slowly came out to greet them. They were so scared that they couldn't move! What could they do? Then the little boy had an idea. He said, "Trick or treat!" Then the big scary monster, much to the kids'surprise, reached over and brought out a huge bowl of the best candies they had never seen. Wow, the kids thought, this was great! It turned out that the house was decorated for Halloween, and the big scary monster was just wearing a costume, just like the kids. Since they were the only kids, and were brave enough to go to the scary house, they could take as much candy as they wanted. It can be inferred from the passage that   _  .
the monster was afraid of the phrase "trick or treat" the two kids were also wearing costumes not all families prepared candy for brave kids some other children had been to the house before the two kids