It seems that the bubble started to burst ______.A

单项选择题

During the six months to the end of June commodities posted their best performance in 35 years, rising by 29%. In July they had their worst month in 28 years, falling by 10%. The slide continues: an index compiled by Reuters, a news agency, shows that prices are almost a fifth below the pinnacle reached in early July. The Economist’s index, which excludes oil, has fallen by over 12%. Breathless headlines have. hailed the bursting of a bubble.
But most analysts are more reticent. They cite various reasons for the recent drop in prices, chief among them the darkening economic outlook in rich countries. In recent weeks it has become clear that Europe and Japan are faring even worse than America, and so are likely to consume less oil, steel, cocoa and the like. But that does not necessarily presage a collapse in commodity prices, they argue, thanks to enduringly strong demand from emerging markets such as China.
Oil consumption, for example, has been falling in rich countries for over two years. Goldman Sachs expects them to use 500,000 fewer barrels a day (b/d) this year than last. But it reckons that decline will be more than offset by an increase of 1.3m b/d in emerging markets. It predicts China’s demand for oil will grow by 5%.
A similar story could be told of many commodities. Marius Kloppers, the boss of BHP Billiton, a huge mining firm presenting its results this week, argued that emerging markets were much more important to the firm’s fortunes than rich ones were. Developing countries, he said, consume four to five times more raw materials per unit of output than rich ones do. He predicted that China’s use of steel, already greater than any other country’s, will double by 2015. China’s continuing and rapid industrialization, he argued, would outweigh any temporary slowdown in exports owing to the weakening world economy.
In terms of supply, however, the picture is more mixed. Farmers, encouraged by high prices, have been planting more grain. Heavy rains in America’s farming heartland earlier in the year did less damage to crops than expected. The International Grains Council, an industry group, now expects a record wheat crop this year, 9% bigger than last year’s. China and India, meanwhile, have produced record amounts of soyabeans, while Thailand and Vietnam have harvested bumper crops of rice. Although stocks of most farm commodities remain alarmingly low, and demand continues to grow, the increasing evidence of a strong supply response has helped to push prices down.

It seems that the bubble started to burst ______.

A. in July with the fall of prices
B. in early July with prices falling by 20%
C. when prices fell except that of oil
D. when prices reached the lowest in 34 years