{"answers": "A", "options": ["f : so among all these reasons for population growth , you don \u2019 t think that housing is one of them , right ? why don \u2019 t you think that housing is the cause ?", "f : although you said that london had a population of about 20 million in 1950 , we don \u2019 t think that education was the cause of population growth .", "f : why don \u2019 t you think that transportation is also the cause of population growth ? what about education then ?", "f : although london has a population of 20 million since 1950 , there is no mention of housing among these reasons for population growth . why ?"], "article": "f : in britain , we are often told that people are leaving the big cities to live in the countryside , but is this the same worldwide ? m : not at all . if you look at the biggest cities in one thousand nine hundred and fifty , 7 out of the top 10 were in the developed countries . but by the year two thousand , the developing countries will have 8 out of top 10. new york , which in one thousand nine hundred and fifty , was number one with a population of around 12,000,000 will only be the sixth the largest city in the world , but with an extra 2 million . f : and london ? m : london , which was number 2 , wo n't even be in the top ten , its population in one thousand nine hundred and fifty , by the way , was about 10,000,000 . f : and why is this happening ? why are people moving to the big cities from the country in the developing countries ? m : the reasons are various , but many are moving to look for work and the problems caused by this are enormous . it said the 26,000,000 people will be living in mexico city by the year two thousand , with sao paulo in brazil , not far behind . f : it 's hard to believe . m : i know . well , just imagine the difficulties this is going to cause in terms of health , transport , an education .", "id": "train_659"}