According to the passage, American schools today have turned into ______. A: a typically bureaucratic organization, highly rigid and impersonal B: an efficient means of supervising educational curricular and ensuring uniformity C: a well organized system competent enough to meet the educational demands of the vast and complex society D: all of the above

The central idea conveyed in the above passage is that______. A: home training is more important than school training in that a child spends so many hours with parents B: teachers can and should help parents to understand the objectives of the school C: parents need to realize how to cooperate with the teachers in educating their children D: parents have unconsciously hindered and obstructed curricular objectives