【正确答案】 A

【答案解析】[听力原文]
In the last 500 years, nothing about people not their clothes, ideas, or languages—has changed as much as what they eat. The original chocolate drink was made from the seeds of a certain kind of tree by South American Indians. The Spanish introduced it to the rest of the world during the 1500s. And although it was very expensive, it quickly became popular. In London, shops where chocolate drinks were served became important meeting places. Some still exist today.
The potato is also from the New World. Around 1600, the Spanish brought it from Peru to Europe, where it soon was widely grown. Ireland became so dependent on it that thousands of Irish people died from hunger when the crop failed during the "Potato Famine" of 1845-1846.
There are many other foods that have travelled from South America to the Old World. But some others went in the opposite direction. Brazil is now the world's largest grower of coffee, and coffee is an important crop in many other countries of South America. But it is native to Ethiopia. It was first made into a drink by Arabs during the 1400s.

The thing about people that has changed the most is