I'm taking a test and have to guess the right answer to the question after the article. Article: Mary got a little white lamb . She tied it to a tree in her field during the day and went to take it home every evening. One evening, she found the lamb gone. Someone had cut the rope and stolen the lamb. When her husband came home, she told him what had happened. Henry at once set out to look for the thief. It was easy to find the thief in the small village. Henry heard that his neighbor Alex got a lamb. He went to the neighbors' house and said angrily, "Return the lamb to me, or I'll call the police." Alex explained that he had bought a lamb, but it was black. Henry looked out of the window. There in the garden was a little black lamb. He felt ashamed. Then he apologized to his neighbour. While they were talking, it began to rain. He stayed in Alex's house until the rain stopped. When he went outside, he was surprised to see the lamb changed. The lamb, which had been black half an hour before, was now almost white. "What colour on earth is the lamb," Henry wondered, "black or white?" Question: Henry didn't leave the neighbor's home _ . Options: A: until it began to rain B: until it stopped raining C: when it was raining D: before it began to rain
A:
B