[单项选择]

Specialization can be seen as a response to the problem of an increasing accumulation of scientific knowledge. By splitting up the subject matter into smaller units, one man could continue to handle the information and use it as the basis for further research. But specialization was only one of a series of related developments in science affecting the process of communication. Another was the growing professionalisation of scientific activity.
No clear-cut distinction can be drawn between professionals and amateurs in salience: exceptions can be found to any role. Nevertheless, the word amateur does carry a connotation that the person concerned is not fully integrated into the scientific community and, in particular, may not fully share its values. The growth of specialization in the nineteenth century, with its consequent requirement of a longer, more complex training, implied greater problems for amateur participation in science. The trend was naturally most obvious in
A. No clear-cut distinction can be drawn between professionals and amateurs in science.
B. Amateurs' participation into scientific research has become more difficult.
C. There is no discriminations of professionals against amateurs in geology.
D. Entrance to professional geological journals has become harder for amateurs.