A、He found a piece of chocolate in his pocket. B、He was given a piece of chocolate by someone. C、He found a large dog by his gat

Albert returned home one evening and found a large dog by his gate. He loved animals very much and as he happened to have a small piece of chocolate in his pocket, he gave it to the dog. The next day, the dog was there again. It held up its head and received another piece of chocolate. Albert called his new friend" Bingo". He never found out the dog’s real name, nor who its owner was. However, Bingo appeared regularly every afternoon and clearly liked chocolate  better than bones. It soon was not satisfied with small pieces of chocolate and wanted a large piece of chocolate every day. If at any time Albert forgot to give it a piece of chocolate, Bingo would get very angry and would refuse to let him open the gate. Now Albert had to spend a large part of his money on chocolate in order to get into his own home! So finally he had to move somewhere else.