This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and health, Subject name: Social & Preventive Medicine
[{'content': 'Multi centre growth reference study (MGRS) all are true except \nSelect and explain. \nA. Paicipating countries were India, Brazil, Ghana Oman, USA, Norway, B. Done by case control study, C. Age group 1-10 years was used, D. Total 8500 breast fed infants and young children paicipated', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Multicentre Growth Reference Study (MGRS) : 1997-2003 Type: Population based study Countries : Brazil, Ghana, India, Oman, Norway, USA Primary growth data and related information gathering from 8440 healthy breast-fed infants and children (0-60 months age) Mother followed breast feeding and not smoking during and after pregnancy New standard generated : Percentile and Z-scores for H for age, W for age, W for L, W for H and BMI for age A key component of the MGRS design was a longitudinal coho of children who were examined in a sequence of 21 visits staing at bih and ending at 24 months of age : Principal rationale for the longitudinal component was to allow for the development of growth velocity standards Ref: Park 25th edition Pgno : 580', 'role': 'assistant'}]