Last summer, 15-year-old Bob had a problem. Like a lot of children, Bob was interested in doing many things. He liked dancing most and wanted to join a dancing group. But Bob's high school didn't have a boys' dancing group but a girls' group. He tried to join the girls' group. And he made it. Bob thought his problem was over after he had been one of the dancers in the dancing group. But a bigger problem was just beginning. The school didn't allow Bob to stay in the girls' group. "If we let Bob stay in the group," the school said, "other boys will want to join, too. Soon, there won't be any girls in the group." They took Bob off the group. Bob was very angry about it, so he went to a judge . The judge said it was not a right decision and told the school to let Bob go back to the dancing group. It was difficult for Bob to join the school dancing group because   _  .
the school only had a girls' dancing group the school didn't allow boys to dance the group had enough dancers already he was not a good dancer