GMAT Sentence Correction (SC) | Re: Native to south america,when peanuts were introduced to

Native to southamerica,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 groundnut, a popular indigenous plant.

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

b.peanuts having been introduced to Africa by Portugese explorers