Explanation:

Fourth option is correct.

Iodine is an essential micronutrient required daily at 100-150 micrograms for normal human growth and development.  Deficiency of iodine can cause physical and mental retardation, cretinism, abortions, stillbirth, deaf mutism, squint & various types of goiter. As per the surveys conducted by the Directorate General of Health Services, Indian Council of Medical Research, Health Institutions and the State Health Directorates, it has been found that out of 414 districts surveyed in all the 29 States and 7 UTs, 337 districts are endemic i.e where the prevalence of Iodine Deficiency Disorders (IDDs) is more than 5% 

Realizing the magnitude of the problem, the Government of India launched a 100 per cent centrally assisted National Goitre Control Programme (NGCP) in 1962.   In August, 1992 the National Goitre Control Programme (NGCP) was renamed as National Iodine Deficiency Disorders Control Programme (NIDDCP) with a view of wide spectrum of Iodine Deficiency Disorders like mental and physical retardation, deaf mutisim, cretinism, still births, abortions etc.. The programme is being implemented in all the States/UTs for entire population.

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