OG verbal 分册一道SC 题目解析不是很清楚。

Native to South America, when peanuts were introduced to africa by Portugese explorers early in the sixteenth century they were quickly adopted into Africa's agriculture, probably because of being so similar to the Bambarra groudnut, a popular indigenous plant.

A.when peanuts were introduced to africa by Portuese explorers early in the sixteenth century they were quickly adopted into Africa's agriculture, probably because of being.

B.Peanuts having been introduced to africa by Portuese explorers early in the sixteenth century and quickly adopted into Africa's agriculture, probably because of being.

C.Peanuts were introduced to africa by Portuese explorers early in the sixteenth century and were quickly adopted into Africa's agriculture, probably because they were.

D.Peanuts, introduced to africa by Portuese explorers early in the sixteenth century and quickly adopted into Africa's agriculture, probably because they were

E.Peanuts, introduced to africa by Portuese explorers early in the sixteenth century and having been quickly adopted into Africa's agriculture, probably because they were.

B的解释是： having been introducted and quickly adopted both introduce adjectival phrases. 这里不太清楚 为什么后面是adjectival phrases。

后面的D、E解释说having been introducted 和 quickly adopted fuction as adjective我就更不明白了。。。

希望能解释得详细一些。谢谢~~~