Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions

In the Native American Navajo nation which sprawls across four states in the American south-west, the native language is dying. Most of its speakers are middle-age or elderly. Although many students take classes in Navajo, the schools are run in English. Street sign, supermarket goods and even their own newspaper are all in English. Not surprisingly, linguists doubt that any native speakers of Navajo will remain in a hundred years' time. 

Navajo is far from alone. Half the world's 6,800 languages are likely to vanish within two generations - that's one language lost every ten days. Never before has the planet's linguistic diversity shrunk at such a pace. Isolation breeds linguistic diversity as a result, the world is peppered with languages spoken by only a few people. Only 250 languages have more than a million speakers, and at least 3,000 have fewer than 2,500. It is not necessarily these small languages that are about to disappear. Navajo is considered endangered despite having 150,000 speakers. 

What makes a language endangered is not that the number of speakers, but how old they are. If it is spoken by children it is relatively safe. The critically endangered languages are those that are only spoken by the elderly, according to Michael Krauss, director of the Alaska Native Language Center, in Fairbanks. 

Why do people reject the language of their parent? It begins with a crisis of confidence, when a small community finds itself alongside a larger, wealthier society, says Nicholas Ostler of Britain's Foundation for Endangered Languages, in Bath. “People lose faith in their culture” he says. "When the next generation reaches their teens, they might not want to be induced into the old tradition.” The change is not always voluntary. Quite often, governments try to kill off a minority language by banning its use in public or discouraging its use in school, all to promote national unity. The former US policy of running Indian reservation in English, for example, effectively put languages such as Navajo on the danger list. But Salikoko Mufwene, who chairs the Linguistics Department at the University of Chicago, argues that the deadliest weapon is not government policy but economic globalisation. "Native Americans have not lost pride in their language, but they have had to adapt to socio-economic pressures" he says. “They cannot refuse to speak English if most commercial activity is in English." However, a growing interest in cultural identity may prevent the direct predictions from coming true. ‘The key to fostering diversity is for people to learn their ancestral tongue, as well as the dominant language' says Doug Whalen, founder and president of the Endangered Language Fund in New Haven, Connecticut. “Most of these will ive without a large degree of bilingualism” he says. 

 It is stated in the passage that the number of endangered languages is ____.

• A. 
  about 3,200
• B. 
  about 6,800
• C. 
  at least 3,000
• D. 
  fewer than 2,500