Pathophysiology of thyroid hormones

How does iodine deficiency lead to hypothyroidism and goiter?

1: By increasing TSH secretion due to low thyroid hormone production
2: By stimulating the autoimmune destruction of the thyroid gland
3: By causing overproduction of thyroid hormones and enlargement of the thyroid gland
4: By reducing the release of thyrotropin-releasing hormone (TRH) from the hypothalamus