As an artist, Jim is certainly an amateur, for he has had no training.
句意:作为一名艺术家,吉姆当然是一个业余爱好者,因为他没有接受过培训。amateur业余爱好者。an alien外星人。a layman门外汉。两者意义最接近。a steward一名管家。因此,本题的正确答案为C。