引起汉堡包需求增加的原因是（）

A、一个新的汉堡包热

B、消费者收入减少了

C、作为互补品的炸薯条的价格上升了

D、作为替代品的包子的价格下降了

Can you imagine life without French fries（炸薯条） ? Potatoes are very popular today. But in the past this was not true. Potatoes grew in South America five thousand years ago. But they only became popular in other places two hundred years ago.In the 1500s, the Spanish took the potato from South America to Europe. But the people in Europe did not like this strange vegetable. Some people thought that if you ate potatoes your skin would look like the skin of a potato. Other people could not believe that you ate the underground part of the plant. So they ate the leaves instead. This made them sick because there is poison（毒性） in the leaves.In the 1800s, people in other parts of the world started to eat potatoes. In Ireland, potatoes became the main food. Then, in 1845, a disease killed all the potatoes in Ireland. Two million people died of hunger.Today, each country has its own potato dish. The German people eat potato salad, and the United States has the baked potato. And, of course, the French invented French fries, which are now popular all over the worldWhen did potatoes get well-known outside South America（）

A.
A．About 200 years ago B.B．About 300 years ago C.C．About 400 years ago D.D．About 500 years ago