全划线的题：
Although at one time children’s programming had been limited to a few hours a week, now, however, there are at least four cable networks that dedicate themselves entirely to shows produced specifically for children.
D. Children’s programming was once limited to a few hours a week, but now there are at least four cable networks dedicated
E. While children’s programming had once been limited to a few hours a week, at least four cable networks are now dedicated
