【单选题】

It is the world’s fourth-most-important food crop, after maize, wheat and rice. It provides more calories, more quickly, using less land and in a wider range of climates than any Other plant. It is, ofCourse, the potato.

The United Nations has declared 2008 the International Year of the Potato. It hopes that greater awareness of the merits of potatoes will contribute to the achievement of its MillenniumDevelopment Goals, by helping to alleviate poverty, improve food security and promote economic development. It is always the international year of this or month of that.But the potato’s unusual history means it is well worth celebrating by readers of TheEconomist because the potato is intertwined with economic development, trade liberalisation and globalisation.
Unlikely though it seems, the potato promoted economic development by underpinning the industrial revolution inEngland in the 19th century. It provided a cheap source of calories and was easy to cultivate, so it liberated workers from the lanD、Potatoes became popular in the north ofEngland, as people there specialised in livestock farming and domestic industry, while farmers in the south (where the soil was more suitable ) concentrated on wheat production.By a happy accident, this concentrated industrial activity in the regions where coal was readily available, and a potato-driven population boom provided ample workers for the new factories. FriedrichEngels even declared that the potato was the equal of iron for its "historically revolutionary role".
The potato promoted free trade by contributing to the abolition ofBritain’sCorn Laws-the cause which prompted the founding of TheEconomist in 1843. TheCorn Laws restricted imports of grain into the United Kingdom in order to protect domestic wheat producers. Landowners supported the laws, since cheap imported grain would reduce their income, but industrialists opposed them because imports would drive down the cost of food, allowing people to spend more on manufactured goods. Ultimately it was not the eloquence of the arguments against theCorn Laws that led to their abolition-and more’s the pity. It was the tragedy of the Irish potato famine of 1845, in which 1million Irish perished when the potato crop on which they subsisted succumbed to blight. The need to import grain to relieve the situation in Ireland forced the government, which was dominated by landowners who backed theCorn Laws, to reverse its position.
This paved the way for liberalisation in other areas, and free trade becameBritish policy.As theDuke of Wellington complained at the time, "rotten potatoes have done it all. "
In the form of French fries, served alongside burgers andCoca-Cola, potatoes are now an icon of globalisation. This is quite a turnaround given the scepticism which first greeted them on their arrival in the Old World in the 16th century. Spuds were variously thought to cause leprosy, to be fit only for animals, to be associated with the devil or to be poisonous. They took hold in 18th centuryEurope only when war and famine meant there was nothing else to eat; people then realised just how versatile and reliable they were.AsAdam Smith, one of the potato’s many admirers, observed at the time, "The very general use which is made of potatoes in these kingdoms as food for man is a convincing proof that the prejudices of a nation, with regard to diet, however deeply rooted, are by no means unconquerable. " Mashed, fried, boiled and roast, a humble tuber changed the world, and free-trading globalisers everywhere should celebrate it.
According to the text, what are the features of potatoesA．Lower price, quicker growing speed, less land required, and wider range of climate.
B．More calories, quicker growing speed, less labor required in growing and processing, and wider range of climate.
C．More calories, quicker growing speed, less land required, and