57. Following clear-cutting of a deciduous forest several hundred years ago, the land was colonized by herbaceous species which, over time, were replaced largely by shrubs, then by forest trees. Assuming the growth of the shrubs and trees was enhanced by the soil-holding properties of the herbaceous plants, which of the following processes best describes the progression from herbaceous plants to forest trees? (A) secondary succession; inhibition. (B) primary succession; toleration. (C) secondary succession; facilitation. (D) primary succession; inhibition. (E) primary succession; facilitation.