The author of this passage holds the view that ______.

参考解析：

细节理解题。A项文中未提及；根据第五段第一句“…easily observable characteristics like having a master’s degree or a passing score on the teacher certification exam are not correlated with teacher effectiveness”可知B项错误；根据倒数第四段“It is not entirely clear whether this experience effect is learning by doing (the more you teach, the more effective you become) or survival of the fittest (those who are not good at teaching tend to drop out early)”，可知C项错误；倒数第三段第二句“however, that teacher effectiveness is pretty clear by the end of the second year”，可知作者同意D项说法，故选D。