关于TPO18 industrialization最后一题的疑问

cz200717UID: 3256695

Although these countries all started with small, uneducated populations, industrialization led to significant population growth and higher literacy rates.

l  Because they all started with good harbors for steamships, these countries started with an important advantage in the competition for transit trade

l  These countries were successful primarily because their high literacy rates helped them fill specialized market niches

l  Thanks to their ready access to the sea. these countries enjoyed advantages in mercantile shipping, fishing, and shipbuilding

l  These countries were helped by the fact that their governments were relatively stable and honest and generally supported liberal trade policies

l  Because they were never fully dependent on international commerce, these countries were able to survive notorious fluctuations in international markets

对于C答案我的疑问是这个primarily，文章貌似只说是一个重要因素，没说是primary factor??

crazyrobinUID: 2368627

这题我是排除法做的。
另外你看下第三段最后一句话， enormous value那句话

后面首句说的都是 important factor 或者 one of the factor

如果这在GRE里就应该算是错误选项。

Anyway, 我觉得对于不确定的排除法是个好方法