The correct option is D I
Plants require seventeen essential minerals for optimum growth. Iodine is not an essential nutrient for plants but is important for animals. In higher animals like humans, iodine is essential for production of thyroxine hormones of thyroid gland and proper development of nervous system during gestation. Deficiency of iodine leads to goitre or swelling of thyroid, reduced mental function, increased abortion still births and infant deaths.