Correct Answer:
B. Iodine
Goitre is a medical condition characterized by an abnormal enlargement of the thyroid gland, which is located in the neck. The thyroid gland plays a crucial role in producing hormones essential for metabolism, growth, and development.
- The correct answer is B: Iodine. Deficiency of iodine is the most common cause of goitre worldwide. The thyroid gland requires iodine to synthesize thyroid hormones (thyroxine and triiodothyronine). When iodine intake is insufficient, the thyroid gland attempts to compensate by growing larger to capture more available iodine, leading to the characteristic swelling known as goitre.
- A: Potassium is an essential electrolyte, but its deficiency does not directly cause goitre.
- C: Protein deficiency can lead to various nutritional problems, but it is not the primary cause of goitre.
- D: all is incorrect because only iodine deficiency is the direct and primary cause among the given options.