Significant Crop from the Columbian Exchange

During the late 15th and early 16th centuries, the voyages of Christopher Columbus and other explorers initiated a massive exchange of goods, plants, animals, and even diseases between the New World (the Americas) and the Old World (Europe, Asia, and Africa). This interchange is referred to as the Columbian Exchange. Which of the following was a significant crop that was introduced to Europe as a result of the Columbian Exchange?