问题详情

When the author refers to professions as no longer being "closed guilds", he means that ______.
A．it is much easier to become a professional today than it was in the past
B．there is more social intercourse between professionals and others
C．popular science has told her secrets to the world
D．anyone can now understand anything in a profession请帮忙给出正确答案和分析，谢谢！