TOEFL Listening: TPO-TOEFL阅读TPO - R70BYUN589289ROZN$

In paragraph 5, why does the author mention the new trade route opened up by Vasco da Gama's fifteenth-century voyage around Africa? A. To provide evidence that European seafarers took every opportunity to bypass Middle Eastern merchants B. To present an instance in which Middle Eastern states lost money and power because of their reliance on long-distance trade C. To argue this new route became necessary when European seafarers wanted to avoid Middle Eastern states whose central power had begun to erode D. To explain how da Gama helped European traders avoid the dangerous predators prowling the areas surrounding Middle Eastern cities