What is the main theme of the novel?

参考解析：

主旨大意题。从第二段第一句话“The main theme is a teenage search of self-discovery, in this case the search for a mother from whom the hero was separated at an early age”可知，主题是青少年对自我发现的探索，在这个情况下，寻找在很小的时候就与之分离的母亲。结合最后一段最后一句“As a journey of self-discovery, The Snake-Stone also provides its readers with a happy ending. Its hero says, on returning to his foster parents, ‘I was home’”可知，作为一个自我发现的旅程，《蛇石》也为读者提供了一个快乐的结局。它的主人公回到养父母身边时说“我在家”。由此可知，该书主题体现在James寻找生身母亲的征途也就是战胜自我获得人生真谛的发现之旅。故选A。