This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Social science, Mental health & Genetics, Subject name: Social & Preventive Medicine
[{'content': 'The following is true about term "New Families\' - \nSelect and explain. \nA. It is variant of the 3-generation family, B. It is applied to all nuclear families of less then 10 years duration, C. It is variant of the joint family, D. It is applied to all nuclear families of less then 2 years duration', 'role': 'user'}, {'content': "Answer: B \nExplanation: - all nuclear families of less then 10 years duration is termed as new families. - the concept is impoant in view of studies relating to family planning. Reference : Park's textbook of preventive and social medicine, 23rd edition, pg no:684 <\\p>", 'role': 'assistant'}]