Read the text and select the correct answer.
"By then, coffee appeared regularly at the tables of many nations, transported there by traders, slaves kidnapped in battle, and religious pilgrims. Historians believe that traders first carried coffee from Africa across the Red Sea to the Arabian Peninsula sometime after the 10th century C.E. By the 15th century, the people of what is now Yemen had adopted coffee and transformed it from a wild plant to a cultivated crop."
Why was coffee transported by groups such as traders, slaves, and pilgrims?
A. They grew their own coffee and traveled to purchase seedlings.
B. They drank a lot of coffee, which made them strong and energetic.
C. They worked at coffeehouses and made deliveries in their areas.
D. They moved around frequently and traveled to different places.