The correct answer is (d), iodine.
Iodine is a trace element that is essential for human health. It is required for the production of thyroid hormones, which are essential for growth and development, metabolism, and brain function. Iodine deficiency can lead to a number of health problems, including goiter, hypothyroidism, and mental retardation.
Seaweeds are an important source of iodine. They can accumulate iodine from seawater, and some species can contain up to 100 times the amount of iodine found in other foods. Iodine-rich seaweeds include kelp, nori, and kombu.
Sulphur, chlorine, and bromine are also trace elements that are essential for human health. However, they are not as readily available from seaweed as iodine is. Sulphur is found in many foods, including meat, poultry, fish, eggs, dairy products, and legumes. Chlorine is found in table salt and in many processed foods. Bromine is found in very small amounts in some foods, such as seafood and dairy products.
In conclusion, the correct answer to the question “Seaweeds are important source of which one of the following?” is (d), iodine.