A 16-year-old asked a stranger at a grocery store to buy him and his mother some food in exchange for carrying the man's groceries to his car. (CET4)What had happened to this boy and his mother?
选项：

A:Maybe some happy stories had happened to them.
B:Maybe some sad and unfortunate stories had happened to them.
C:Maybe some exciting things had happened to them.
D:Maybe some lucky things had happened to them.