题目内容：
C． Clone Farm1 Factory farming could soon enter a new era of mass production. Companies in the US are developing the technology needed to "clone" chickens on a massive scale1. Once a chicken with desirable traits has been bred or genetically engineered2, tens of thousands of eggs, which will hatch into identical copies3 , could roll off the production lines every hour. Billions of clones could be produced each year to supply chicken farms with birds that all grow at the same rate, have the same amount of meat and taste the same.
2 This, at least, is the vision of the US's National Institute of Science and Technology, which has given Origen Therapeutics of Burlingame, California, and Embrex of North Carolina $4.7 million to help fund research4. The prospect has alarmed animal welfare groups, who fear it could increase the suffering of farm birds.
3 That's unlikely to put off5 the poultry industry, however, which wants disease-resistant birds that grow faster on less fooD． "Producers would like the same meat quantity but to use reduced inputs to get there," says Mike Fitzgerald of Origen. To meet this demand, Origen aims to "create an animal that is effectively a clone", he says. Normal cloning doesn't work in birds because eggs can't be removed and implanteD． Instead, the company is trying to bulk-grow6, embryonic stem cells7 taken from fertilized eggs as soon as they're laiD． "The trick is to culture8 the cells without them starting to distinguish, so they remain pluripotent," says FitzgeralD．
4 Using a long-established technique, these donor cells will then be injected into the embryo of a freshly laid, fertilized recipient egg9, forming a chick that is a "chimera". Strictly speaking a chimera isn't a clone, because it contains cells from both donor and recipient. But Fitzgerald says it will be enough if, say, 95 percent of a chicken's body develops from donor cells. "In the poultry world, it doesn't matter if it's not 100 percent," he says.
5 Another challenge for Origen is to scale up10 production. To do this, it has teamed up with11 Embrex, which produces machines that can inject vaccines into up to 50,000 eggs12 an hour. Embrex is now trying to modify the machines to locate the embryo and inject the cells into precisely the right spot without killing it.
6 In future, Origen imagines freezing stem cells from different strains of chicken13. If orders come in for a particular strain, millions of eggs could be produced in months or even weeks. At present, maintaining all the varieties the market might call for is too expensive for breeders, and k takes years to breed enough chickens to produce the billions of eggs that farmers neeD．
阅读短文，回答题。
Which statement is the best description of the new era of factory farming according to the first paragraph? A．Eggs are all genetically engineereD．
B．Thousands of eggs are produced every hour.
C．Cloned chickens are bulk-produced with the same growth rate, weight and taste.
D．Identical eggs can be hatched on the production lines.
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